JP2002365763A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having low fog, high Dmax(maximum density) and good preservability before and after development. SOLUTION: The heat developable photosensitive material contains photosensitive silver halide, a non-photosensitive organic silver salt, a reducer for silver ions, a binder, a polyhalogenomethylsulfonyl compound of formula (1) (where Z<1> and Z<2> are each halogen; A is H or halogen; R<1> is alkyl or the like) and a compound of formula (2) (where Z<3> is alkyl or the like; W is aryl or the like; and M is a counter cation) on one face of the support.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly to a scanner suitable for photolithography.
More particularly, the present invention relates to a photothermographic material for photolithography, which has a low fog, a high Dmax (maximum density), and a good storability before and after a development process.

[0002]

2. Description of the Related Art A photosensitive image forming layer is provided on a support,
Many photosensitive materials that form an image by image exposure are known. Among them, there is a technique of forming an image by thermal development as a system that contributes to environmental conservation and can simplify an image forming unit. In recent years, in the field of photoengraving, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental conservation and space saving. Therefore, there is a need to develop a technology relating to a photothermographic material for photolithography, which can be efficiently exposed by a laser scanner or a laser imagesetter and can form a sharp black image having high resolution and sharpness. is needed. According to such a photothermographic material, it is possible to supply a customer with a simpler and more environmentally friendly photothermographic processing system that does not require solution-based processing chemicals.

A method of forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,4,904.
57,075, and D.C. Crosta Bohr (Kl
osterboer) “Thermally Processed Silver Systems A” (Imaging Processes and Materials (Imag)
ing Processes and Materials) Neblette 8th edition, J.M.
Sturge, V.S. Walworth
h), A. Edited by Shepp, Chapter 9, page 279,
1989). Such photothermographic materials typically comprise a non-photosensitive reducible silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent dispersed in an organic binder matrix. It is contained in a state. The photosensitive material is stable at room temperature, but when heated to a high temperature (for example, 80 ° C. or more) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate This oxidation-reduction reaction is promoted by the catalytic action of the latent image formed by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas becomes black and forms an image because it contrasts with the unexposed areas.

Conventionally known photothermographic materials are:
In many cases, the image forming layer is formed by applying a coating solution using an organic solvent such as toluene, methyl ethyl ketone (MEK), or methanol as a solvent. The use of an organic solvent as a solvent not only adversely affects the human body in the manufacturing process, but also disadvantageous in cost because a solvent recovery and other steps are required.

Accordingly, a method has been proposed in which an image forming layer is formed by using a coating solution containing water as a solvent. For example, JP-A-49-52626, JP-A-53-116144
Japanese Patent Application Publication No. JP-A-2005-133125 describes an image forming layer using gelatin as a binder. JP-A-50-151138 discloses an image forming layer using polyvinyl alcohol as a binder. Further, JP-A-60-617
No. 47 describes an image forming layer using a combination of gelatin and polyvinyl alcohol. As another example, JP-A-58-28737 describes an image forming layer using water-soluble polyvinyl acetal as a binder. If such a binder is used, the image forming layer can be formed using a coating solution of a water solvent,
Environmental and cost benefits are significant.

EP-A-762,196A, JP-A-9-90550 and the like contain photosensitive silver halide grains used in a photothermographic material containing a metal ion or metal complex ion of Group VII or VIII. ,
In addition, it discloses that a hydrazine derivative can be contained in a light-sensitive material to obtain high-contrast photographic characteristics. However, when a nucleating agent such as hydrazine is used in combination with the binder used in the aqueous solvent coating solution, a high-contrast image can be obtained.

In general, when using a film for photoengraving in the field of newspaper printing or commercial printing, there has been a demand for a system capable of obtaining a stable image at any time. However, since the silver halide and silver ion reducing agents are still present in the film, the generation of metallic silver continues to occur even when handled with room light, and the density of the lowest density part (Dmin) increases. There was a case. Japanese Patent Application Laid-Open No. 2001-31644 describes a polyhalogenomethylsulfonyl compound having a carbamoyl group as a measure for improving the image storability after the above-mentioned processing, and is particularly used in the fields of newspaper printing and commercial printing. In the case of a photothermographic material having high-contrast photographic characteristics, this effect is small and insufficient, and there is a problem that storage stability before development and Dmax are not compatible. Therefore, it has been desired to provide a photothermographic material having low fog, high Dmax (highest density), and good storage stability before and after development processing.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a low fog and high Dmax, especially for photolithography, especially for scanners and imagesetters.
Another object of the present invention is to provide a photothermographic material having a (highest density) and good storage stability before and after the development processing.

[0009]

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using two types of compounds having a specific structure in combination, and have reached the present invention. did. That is, the present invention provides a method for preparing a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, a binder, a polyhalogenomethylsulfonyl compound represented by the following formula (1) on one surface of a support. And a compound represented by the following formula (2):

Embedded image (In the formula (1), Z ¹ and Z ² each independently represent a halogen atom, A represents a hydrogen atom or a halogen atom, and R ¹
Is an alkyl group having 2 to 12 carbon atoms which may have one or more substituents, an alkenyl group having 2 to 12 carbon atoms which may have one or more substituents, or 1
Or 2 to 1 carbon atoms which may have two or more substituents
2 represents an alkynyl group. The substituent which the alkyl group, alkenyl group or alkynyl group represented by R ¹ may have is a halogen atom; an alkoxy group; a nitro group; an amino group optionally substituted by an alkyl group; an alkoxycarbonyl group; A silyl group; an alkylthio group; and one or more substituents selected from the group consisting of heterocyclic groups. )

Embedded image (In the formula (2), Z ³ represents an alkyl group optionally having one or more substituents, an aryl group optionally having one or more substituents, or 1 or 2 Represents a heterocyclic group optionally having at least two substituents, and W represents an aryl group optionally having one or more substituents, or an alkyl group substituted with an electron-withdrawing group And M represents a counter cation.)

In the formula (1), Z ¹ and Z ² are each a bromine atom, A is preferably a hydrogen atom or a bromine atom, and R ¹ is an unsubstituted alkyl group having 2 to 12 carbon atoms. is preferably a substituted alkenyl group or an unsubstituted alkynyl group having 2 to 12 carbon atoms having 2 to 12 carbon atoms, alkyl group of R ¹ is unsubstituted 3 to 5 carbon atoms, an unsubstituted carbon atoms 3 An alkenyl group of 5 or an unsubstituted carbon number of 3 to
5 is an alkynyl group, preferably -CONHR
It is preferable ^{that 1} is in the meta position with respect to ^{_{-SO 2 C (Z 1) (}} Z 2) A.

The photothermographic material of the present invention can be exposed in 10 ^-6 seconds or less. Further, the photothermographic material of the present invention can be exposed with a multi-beam having two or more laser heads. Further, the photothermographic material of the present invention can be subjected to heat development at a line speed of 140 cm / min or more.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photothermographic material of the present invention will be described below in detail. In this specification, “to” indicates a range including numerical values described before and after it as a minimum value and a maximum value, respectively. The photothermographic material of the present invention has a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, and a binder on one surface of a support. The feature is that the polyhalogenomethylsulfonyl compound represented by the above formula (1) and the compound represented by the above formula (2) are used in combination.

First, the polyhalogenomethylsulfonyl compound represented by the above formula (1) will be described in detail. In the formula (1), Z ¹ and Z ² each independently represent a halogen atom, and the halogen atom mentioned here may be any of fluorine, chlorine, bromine and iodine. Most preferably, Z ¹ and Z ² are both bromine atoms. In the formula (1), A represents a hydrogen atom or a halogen atom, and the halogen atom mentioned here may be any of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Preferably, A is a halogen atom, particularly preferably a bromine atom. Most preferably, in formula (1), Z ¹ , Z ² and A are all bromine atoms.

In the formula (1), R ¹ is an alkyl group having 2 to 12 carbon atoms which may have one or more substituents, and has one or more substituents. Represents an alkenyl group having 2 to 12 carbon atoms or an alkynyl group having 2 to 12 carbon atoms which may have one or more substituents. The alkyl group, alkenyl group or alkynyl group may be linear, branched or cyclic, or a combination thereof. Linear or branched carbon number 2-12
Examples of the alkyl group include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group,
sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and the like. Is a cyclopropyl group, a cyclobutyl group, a cyclopentyl group,
Cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl and the like. 2 carbon atoms
Examples of the 12 alkenyl groups or alkynyl groups include groups in which at least one carbon-carbon single bond in the above alkyl group has been replaced with a double bond and / or a triple bond.
Preferred examples of the alkyl group include an isopropyl group and n-
A butyl group, a cyclopentyl group and the like are mentioned, and preferable examples of the alkenyl group include an allyl group and a 2-butenyl group, and preferable examples of the alkynyl group are
And a propargyl group and a 2-butynyl group.

In the formula (1), the alkyl group, alkenyl group or alkynyl group represented by R ¹ may have one or more substituents. (Journal of Medical Chemistry, 1973, 1
207) is preferably -0.3 or more. Specific examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, and a bromine atom),
An alkoxy group (eg, methoxy group, ethoxy group, etc.), a nitro group, an amino group optionally substituted by an alkyl group (eg, dimethylamino group, etc.), an alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.) ), Acylthio group (eg, acetylthio group, etc.), silyl group, alkylthio group (eg,
Methylthio group, ethylthio group, etc.), heterocyclic group [for example, monocyclic having one or more hetero atoms (nitrogen atom, oxygen atom, sulfur atom, etc.) as ring-constituting atoms,
A cyclic or tricyclic heterocyclic group, which may be an alicyclic group or an aromatic group, and wherein one or more rings contained in the heterocyclic group are partially or completely saturated It may be. For example, imidazolyl group, triazolyl group, tetrazolyl group, thiadiazolyl group, thiazolyl group, oxazolyl group and the like]. Note that a preferable substituent is a halogen atom or an alkoxy group. When two or more substituents are present, these substituents may be the same or different. R ¹ is preferably an unsubstituted alkyl, alkenyl or alkynyl group.

R ^{1 in the} formula (1) is preferably an unsubstituted alkyl group having 3 to 5 carbon atoms or an unsubstituted alkenyl group having 3 to 5 carbon atoms, particularly preferably 4 or 5 carbon atoms.
Is an unsubstituted alkyl group.

In the formula (1), -SO ₂ -C (Z ¹ ) (Z
² ) (A) and -CONHR ¹ may be ortho-substituted, meta-substituted or para-substituted with each other, but most preferably meta-substituted. In the formula (1), Z ¹ , Z ² and A are all bromine atoms, and —SO ₂ —C (Z ¹ )
The case where (Z ² ) (A) and —CONHR ¹ are meta-substituted with each other is one of the most preferred embodiments of the present invention.

The compound represented by the formula (1) used in the present invention may form an acid addition salt, and the acid addition salt is included in the scope of the present invention. As the acid addition salt, for example,
In addition to mineral salts such as hydrochloride, hydrobromide, nitrate, sulfate, and phosphate, p-toluenesulfonate, methanesulfonate, oxalate, tartrate, malate, and citric acid Organic acid salts such as salts can be mentioned. Further, depending on the type of the substituent, a base addition salt may be formed. Further, the compounds of the present invention may exist as hydrates or solvates. All of these salts, hydrates or solvates are included in the scope of the present invention.

The compound used in the present invention may have one or more asymmetric carbons depending on the type of the substituent. In such a case, stereoisomers such as optical isomers based on one or more asymmetric carbons and diastereoisomers based on two or more asymmetric carbons may exist. Any stereoisomers in pure form, any mixtures of stereoisomers, racemates and the like are all included in the scope of the present invention. When R ¹ represents an alkenyl group which may have a substituent in the formula (1), a geometrical isomer may be present due to a double bond present in the alkenyl group. Any geometric isomer, any mixture of geometric isomers, and the like are included in the scope of the present invention.

The compound represented by the formula (1) used in the present invention can be prepared by a method well known in the art. Specific examples of the compound of the formula (1) are shown below,
The present invention is not limited to this.

[0021]

Embedded image

[0022]

Embedded image

[0023]

Embedded image

[0024]

Embedded image

[0025]

Embedded image

The compound represented by the formula (1) used in the present invention can be used in a heat-developable image recording material.
In such a case, the compound represented by the formula (1) may be prepared from water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), dimethylformamide, It can be used by dissolving it in dimethyl sulfoxide, methyl cellosolve or the like. Further, the compound having an acidic group bonded thereto may be neutralized with an equivalent amount of alkali and used as a salt.

Further, by an emulsification dispersion method well known in the art, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate or an auxiliary solvent such as ethyl acetate or cyclohexanone is used for dissolving and mechanically dispersing. To prepare a heat-developable image recording material. Alternatively, by a method known as a solid dispersion method, the powder is dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Manton-Gaulin, a microfluidizer, or ultrasonic waves, and used in a heat-developable image recording material. it can.

The type of the heat-developable image recording material in which the compound represented by the formula (1) can be used is not particularly limited, but an image containing an organic silver salt as a reducible silver salt and a binder on a support is preferred. It is preferable that the layer on the image forming layer side contains a reducing agent and further contains a photosensitive silver halide, and the image forming layer is a photosensitive layer containing a photosensitive silver halide. Is preferred. For example, European Patent Publication No. EP0803764A1 can be referred to. When the compound represented by the formula (1) is used in a heat-developable image recording material, it is preferable that the compound represented by the formula (1) is contained in a layer on the image forming layer side with respect to the support. That is, the compound represented by the formula (1) may be contained in the image forming layer, or may be contained in another layer on the image forming layer side, particularly preferably in the image forming layer or a layer adjacent thereto. include.

The amount of the compound represented by the formula (1) used in the heat-developable image recording material of the present invention is 1 × 10 ^-6 to 1 mol per mol of silver used in the heat-developable image recording material.
l, preferably 1 × 10 ^{-5 to} 5 × 10 ^-1 mol, more preferably 2 × 10 ^-5 to 2 × 10 ^-1 mol.
Is

Next, the compound of the formula (2) used in the present invention will be described. In the formula (2), Z ³ represents an alkyl group [a linear, branched, or cyclic substituted or unsubstituted alkyl group. They have an alkyl group (preferably having 1 to carbon atoms).
30 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-
Octyl, eicosyl, 2-chloroethyl, 2-
A cyanoethyl group, a 2-ethylhexyl group, a trichloromethyl group, a trifluoromethyl group), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, for example, a cyclohexyl group, a cyclopentyl group, n-dodecylcyclohexyl group), bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, 5 carbon atoms)
It is a monovalent group obtained by removing one hydrogen atom from ~ 30 bicycloalkanes. For example, a bicyclo [1.2.2] heptane-2-yl group, a bicyclo [2.2.2] octan-3-yl group), and a tricyclo structure having many ring structures are also included. An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, o or m or a p-methanesulfonylphenyl group, , 5-bistrifluoromethyl group, o-hexadecanoylaminophenyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and one hydrogen atom And more preferably a monovalent group, more preferably having 3 carbon atoms
~ 30 5- or 6-membered aromatic heterocyclic group.
For example, it represents a 2-furyl group, a 2-thienyl group, a 2-pyrimidinyl group, or a 2-benzothiazolyl group).

Z ³ is preferably an alkyl group or an aryl group.

Z ³ may be further substituted with another substituent. Examples of the substituent include a halogen atom, an alkyl group (including a cycloalkyl group and a bicycloalkyl group), and an alkenyl group (a cycloalkenyl group and a bicycloalkenyl group). ), Alkynyl group, aryl group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyl Oxy group, aryloxycarbonyloxy, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, Capto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and hetero Examples include a ring azo group, an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, and a silyl group.

In the formula (2), W represents an aryl group or an alkyl group substituted with an electron-withdrawing group.

The aryl group represented by W has the same meaning as the aryl group described above for Z ³ . The aryl group may be further substituted with another substituent, and this substituent has the same meaning as the substituent of Z ³ . The aryl group represented by W is preferably substituted by at least one electron-withdrawing group. The electron-withdrawing group is defined by Hammett's substituent constant σp
Is a substituent that can take a positive value, specifically,
A cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a thiocarbonyl group, a sulfamoyl group,
Alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom, perfluoroalkyl group, perfluoroalkaneamide group, sulfonamide group, acyl group,
Formyl group, phosphoryl group, carboxy group, sulfo group (or salt thereof), heterocyclic group, alkenyl group, alkynyl group, acyloxy group, acylthio group, sulfonyloxy group, or aryl group substituted with these electron-withdrawing groups And so on.

The alkyl group represented by W has the same meaning as the alkyl group described above for Z ³ , but at least one or more electron-withdrawing groups must be substituted. The definition of the electron-withdrawing group is as described above.

W is preferably an alkyl group substituted with an electron-withdrawing group.

In the formula (2), M represents a counter cation. For example, hydrogen ions, metal cations (eg, Na, K, Ca, Mg, Zn, Ag, etc.), ammonium cations (eg, NH ₄ , tetramethylammonium,
Tetrabutylammonium, benzyltrimethylammonium, etc.). Preferably, they are a metal cation and an ammonium cation.

The compound of the formula (2) used in the present invention may incorporate an adsorptive group that adsorbs to silver halide. Examples of such an adsorptive group include U.S. Pat. JP-A-59-195233, JP-A-59-2
Nos. 00231 and 59-201045 and 5
JP-A-9-201046, JP-A-59-201047, JP-A-59-201048, and JP-A-59-20104
No. 9, JP-A-61-170733 and JP-A-61-170733.
270744, 62-948, 63-
The groups described in JP-A-234244, JP-A-63-234245, and JP-A-63-234246 are exemplified. These adsorbing groups to silver halide may be precursors. Examples of such a precursor include groups described in JP-A-2-285344.

The compound of the formula (2) used in the present invention is
A ballast group or a polymer commonly used in immobile photographic additives such as couplers may be incorporated therein. Particularly, those incorporating a ballast group are one of preferred examples of the present invention. 8 ballast groups
A group having the above number of carbon atoms, which is relatively inert to photographic properties.For example, select from an alkyl group, an aralkyl group, an alkoxy group, a phenyl group, an alkylphenyl group, a phenoxy group, an alkylphenoxy group, and the like. Can be. As the polymer, for example, JP-A-1-1005
No. 30 publication.

The compound of the formula (2) used in the present invention is
The repeating unit of a cationic group (specifically, a group containing a quaternary ammonium group, or a nitrogen-containing heterocyclic group containing a quaternized nitrogen atom, etc.), an ethyleneoxy group or a propyleneoxy group is contained therein. Group, an (alkyl, aryl, or heterocyclic) thio group, or a dissociable group dissociable by a base (such as a carboxy group, a sulfo group, an acylsulfamoyl group, or a carbamoylsulfamoyl group). Good. Particularly, a group containing a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group or a group containing an (alkyl, aryl, or heterocyclic) thio group is one of preferred examples of the present invention. Specific examples of these groups include, for example, JP-A-7-234471.
JP, JP-A-5-333466, JP-A-6-1
No. 9032, JP-A-6-19031, JP-A-5-45761, US Pat. No. 4,994,365, US Pat. No. 4,988,604, JP-A-73-2
Compounds described in JP-A-59240, JP-A-7-5610, JP-A-7-244348, German Patent 4006032 and the like can be mentioned.

The molecular weight of the compound of the formula (2) used in the present invention is preferably 50 to 10,000, more preferably 100 to 2,000, and particularly preferably 30 to 2,000.
0 to 1000.

The compound represented by the formula (2) used in the present invention can be prepared by a method well known in the art. Specific examples of the compound of the formula (2) are shown below,
The compounds that can be used in the present invention are not limited to these.

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

The compound of the formula (2) used in the present invention is
It can be used by dissolving it in water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, methyl cellosolve and the like.

Further, by using a well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone is used to dissolve and dissolve. An emulsified dispersion can be prepared and used. Alternatively, the powder can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Manton-Gaulin, a microfluidizer, or an ultrasonic wave by a method known as a solid dispersion method.

The compound of the formula (2) used in the heat-developable image recording material of the present invention may be added to any layer on the image forming layer side with respect to the support. It is preferable to add it to an adjacent layer.

The amount of the compound of the formula (2) used in the heat-developable image recording material of the present invention is 1 × 1 to 1 mol of silver.
0 ^{-5 to} 1 mol is preferable, and 1 × 10 ^{-4 to} 5 × 10 ^-1 m
ol is more preferable, and 2 × 10 ⁻⁴ to 2 × 10 ⁻¹ mol is most preferable. The compound of the formula (2) used in the present invention may be used alone or in combination of two or more.

In the present invention, in order to form a super-high contrast image, a high contrast accelerator can be used in combination with the above-mentioned compound. For example, amine compounds described in U.S. Pat. No. 5,545,505, specifically AM-1 to AM-5,
Hydroxamic acids described in U.S. Pat. No. 5,545,507, specifically HA-1 to HA-11, acrylonitriles described in U.S. Pat. No. 5,545,507, specifically CN-1 to CN-13, hydrazine compounds described in U.S. Pat. No. 5,558,983, specifically, CA-1 to CA-6, JP-A-9-297.
No. 368, onium salts, specifically A-
1 to A-42, B-1 to B-27, C-1 to C-14 and the like can be used.

The organic silver salt that can be used in the present invention is
Relatively stable to light, but forms a silver image when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. It is a silver salt. The organic silver salt can be any organic material including a source of reducible silver ions. Silver salts of organic acids,
Particularly (having 10 to 30 carbon atoms, preferably 15 to 28 carbon atoms)
Silver salts of long chain fatty carboxylic acids are preferred. The ligand is 4.0
Complexes of organic or inorganic silver salts having a complex stability constant in the range of from 10.0 to 10.0 are also preferred. The silver donor can preferably comprise about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. In particular,
Examples thereof include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include:
Silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and Silver camphorate and mixtures thereof can be mentioned.

In the present invention, in the above-mentioned organic acid silver or a mixture of the organic acid silver, a silver behenate content of 75 m
ol% or more of organic acid silver, more preferably 85% by mole or more of silver behenate. Here, the content of silver behenate indicates the mole fraction of silver behenate with respect to the organic acid silver used. As the organic acid silver other than silver behenate contained in the organic acid silver used in the present invention, the above-mentioned exemplified organic acid silver can be preferably used.

The organic acid silver which is preferably used in the present invention is
It is prepared by reacting silver nitrate with a solution or suspension of the above-mentioned alkali metal salt of an organic acid (including Na salt, K salt, Li salt and the like). These preparation methods are described in paragraph No. 00 of JP-A-2000-292882.
The methods described in 19 to 0021 can be used.

In the present invention, a method of preparing an organic silver salt by adding an aqueous solution of silver nitrate and a solution of an alkali metal salt of an organic acid into a sealing means for mixing a liquid can be preferably used. Specifically, JP-A-200
The method described in 1-333907 can be used. In the present invention, a water-soluble dispersant can be added to the aqueous silver nitrate solution and the organic acid alkali metal salt solution or the reaction solution during the preparation of the organic acid silver.
Specific examples of the type and amount of the dispersant used here are described in JP-A-2000-305214, paragraph 0052.

The silver salt of an organic acid used in the present invention is preferably prepared in the presence of a tertiary alcohol. As the tertiary alcohol, a compound having a total carbon number of 15 or less is preferable, and a compound having a total carbon number of 10 or less is particularly preferable. Preferred examples of the tertiary alcohol include tert-butanol, but the tertiary alcohol that can be used in the present invention is not limited to this. The tertiary alcohol used in the present invention may be added at any time during the preparation of the organic acid silver salt.
It is preferable to dissolve and use the organic acid alkali metal salt. Further, the tertiary alcohol used in the present invention is 0.01 to 1 in mass ratio to water as a solvent at the time of preparing the silver salt of an organic acid.
Although it can be used in the range of 0, it is preferable to use in the range of 0.03-1.

The shape and size of the organic silver salt which can be used in the present invention are not particularly limited.
It is preferable to use those described in paragraph No. 0024 of No. 2882. The shape of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. Another method for measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic silver salt. The percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 80% or less, Preferably not more than 50%, more preferably 30%
% Or less. As a measuring method, for example, an organic silver salt dispersed in a liquid is irradiated with a laser beam, and an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained from a particle size (volume weighted average diameter) obtained. be able to. The average particle size in this measurement method is 0.1.
A solid fine particle dispersion of from 0.05 μm to 10.0 μm is preferred. A more preferred average particle size is 0.1 μm to 5.0.
μm, more preferably the average particle size is 0.1 μm to
2.0 μm.

The organic silver salt used in the present invention is preferably desalted. The desalting method is not particularly limited, and known methods can be used, but centrifugal filtration, suction filtration,
Known filtration methods such as ultrafiltration and floc-forming water washing by a coagulation method can be preferably used. As a method for ultrafiltration, a method described in JP-A-2000-305214 can be used.

In the present invention, in order to obtain a solid dispersion of an organic silver salt having a high S / N, a small particle size and no aggregation, an organic silver salt which is an image forming medium and a photosensitive silver salt are substantially contained. It is preferable to use a dispersion method in which a water dispersion liquid which is not included in the liquid is converted into a high-speed flow and then the pressure is reduced. As for these dispersion methods, the methods described in Paragraph Nos. 0027 to 0038 of JP-A-2000-292882 can be used.

The particle size distribution of the organic silver salt solid fine particle dispersion used in the present invention is preferably monodispersed. Specifically, the percentage (coefficient of variation) of the value obtained by dividing the standard deviation of the volume load average diameter by the volume load average diameter is 80% or less, more preferably 50% or less, and still more preferably 30% or less.

The organic silver salt solid fine particle dispersion used in the present invention comprises at least an organic silver salt and water. The ratio of the organic silver salt to water is not particularly limited, but the ratio of the organic silver salt to the whole is preferably 5 to 50% by weight, and particularly preferably 10 to 30% by weight.
Although it is preferable to use the above-mentioned dispersing aid, it is preferable to use the dispersing aid in the minimum amount within a range suitable for minimizing the particle size.
A range of 15% by weight is preferred.

The organic silver salt used in the present invention can be used in a desired amount, but the silver amount is preferably 0.1 to 5 g / m ² ,
More preferably, it is 1 to 3 g / m ² .

In the present invention, it is preferable to add a metal ion selected from Ca, Mg, Zn and Ag to the non-photosensitive organic silver salt. Regarding addition of metal ions selected from Ca, Mg, Zn and Ag to the non-photosensitive organic silver salt,
It is preferably added in the form of a water-soluble metal salt which is not a halide, and specifically, it is preferably added in the form of a nitrate or a sulfate. The addition of a halide is not preferable because it deteriorates the image storability of the processed photosensitive material due to light (such as room light or sunlight), that is, the so-called printout property. For this reason, in the present invention, it is preferable to add in the form of a water-soluble metal salt which is not a halide.

Ca, Mg, Zn preferably used in the present invention
The addition time of the metal ion selected from Ag and Ag may be any time after the formation of the particles of the non-photosensitive organic silver salt and immediately before the coating, such as immediately after the formation of the particles, before the dispersion, after the dispersion and before and after the preparation of the coating solution. It may be during the period, preferably after dispersion and before and after preparation of the coating solution.

In the present invention, Ca, Mg, Zn and A
The addition amount of the metal ion selected from g is preferably 10 ^-3 to 10 ^-1 mol, and particularly preferably 5 × 10 ^{-3 to} 5 × 10 ^-2 mol, per 1 mol of non-photosensitive organic silver.

The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and may be silver chloride, silver chlorobromide,
Silver bromide, silver iodobromide, silver iodochlorobromide can be used. The grain formation of the photosensitive silver halide emulsion is described in paragraphs 0217 to 0217 of JP-A-11-119374.
The particles can be formed by the method described in H.224, but the method is not particularly limited to this method. The shapes of silver halide grains are cubic, octahedral, tetradecahedral,
Tabular, spherical, rod-like, potato-like and the like can be mentioned. In the present invention, cubic particles or tabular particles are particularly preferable. The characteristics of the particle shape such as the particle aspect ratio and the surface index are described in JP-A-11-119374.
It is the same as that described in Paragraph No. 0225 of the publication. The distribution of the halogen composition may be uniform inside and on the surface of the silver halide grains, and the halogen composition may be changed stepwise or may be changed continuously. Further, silver halide grains having a core / shell structure can be preferably used.
As the structure, core / shell particles having preferably a 2- to 5-layer structure, more preferably a 2- to 4-layer structure, can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

The size of the silver halide grains of the photosensitive silver halide used in the present invention can be used without any particular limitation.
It is preferably from 0.1 to 0.10 μm. The particle size distribution of the silver halide grains used in the present invention is such that the value of monodispersity is 30% or less, preferably 1 to 20%, and more preferably 5 to 15%.
It is. Here, the monodispersity is defined as a percentage (%) (coefficient of variation) of a value obtained by dividing the standard deviation of the particle size by the average particle size. For the sake of convenience, the grain size of silver halide grains is represented by a ridge length in the case of cubic grains, and other grains (octahedral, tetradecahedral, tabular, etc.) are calculated by projected area circle equivalent diameters.

The photosensitive silver halide grains used in the present invention
Is a metal of Group VII or VIII of the Periodic Table
Or it contains a metal complex. Group VII of the periodic table
Or a group VIII metal or a central metal of a metal complex.
And preferably rhodium, rhenium, ruthenium, osuni
And iridium. Particularly preferred metal complexes are
(NH_Four)_ThreeRh (H_TwoO) Cl_Five, K_TwoRu (NO) C
l_Five, K_ThreeIrCl₆, K_FourFe (CN)₆It is. these
One kind of metal complex may be used,
May be used in combination of two or more. Preferred content is silver
1 × 10 for 1 mol^-9mol ~ 1 × 10^-3mol
Preferably in the range 1 × 10^-8mol ~ 1 × 10 ^-Fourmol
Is more preferable. Specific structure of metal complex
Has a structure described in JP-A-7-225449 and the like.
Metal complexes can be used. The types of these heavy metals,
Regarding the addition method, see JP-A-11-119374.
Paragraph Nos. 0227 to 0240 are described.

The photosensitive silver halide grains can be desalted by a water washing method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted. . The photosensitive silver halide emulsion used in the present invention is preferably chemically sensitized. The chemical sensitization is described in paragraph No. 02 of JP-A-11-119374.
It is preferable to use the methods described in JP-A Nos. 42 to 0250. A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention by a method described in European Patent Publication EP 293,917A.

As the gelatin contained in the photosensitive silver halide used in the present invention, a low-molecular-weight gelatin is used in order to maintain a good dispersion state of the photosensitive silver halide emulsion in a coating solution containing an organic silver salt. Is preferred. The low molecular weight gelatin has a molecular weight of 500 to 60,000, preferably 1,000 to 40,000. These low molecular weight gelatins may be used at the time of grain formation or at the time of dispersion after desalting, but are preferably used at the time of dispersion after desalting. When forming particles, use normal gelatin (molecular weight of about 100,000),
Low-molecular-weight gelatin may be used at the time of dispersion after desalting.

The concentration of the dispersion medium can be 0.05 to 20% by mass, but a concentration range of 5 to 15% by mass is preferable for handling. As the type of gelatin, alkali-treated gelatin is usually used, and in addition, acid-treated gelatin,
Modified gelatin such as phthalated gelatin can also be used.

As the silver halide emulsion in the light-sensitive material used in the present invention, only one kind may be used, or two or more kinds may be used (for example, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different chemical sensitization conditions).

The amount of the photosensitive silver halide used in the present invention is preferably 0.01 mol to 0.5 mol, more preferably 0.02 mol to 1 mol of the organic silver salt.
mol to 0.3 mol, more preferably 0.03 mol
~ 0.25 mol is particularly preferred. Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the silver halide particles and the organic silver salt which have been respectively prepared are mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, a vibration mill, There is a method of mixing with a homogenizer or the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt. There is no particular limitation as long as it is sufficiently obtained. Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts is a preferable method for adjusting photographic characteristics.

The sensitizing dye which can be used in the present invention is one capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and is suitable for the spectral characteristics of an exposure light source. Sensitizing dyes having spectral sensitivity can be advantageously selected. For example, 550 nm to 750 n
As a dye for spectrally sensitizing a wavelength region of m
And dyes represented by the general formula (II) of JP-A-186572, specifically, II-6, II-7, and II-1.
4, II-15, II-18, II-23, II-25
Can be exemplified as preferred dyes. Examples of the dye that spectrally sensitizes the wavelength region of 750 to 1400 nm include a dye represented by the general formula (I) in JP-A-11-119374.
5), (26), (30), (32), (36), (3)
The dyes of 7), (41), (49) and (54) can be exemplified as preferred dyes. Furthermore, J-ban
US Pat. No. 5,510,23 as a dye forming d.
And the dyes described in Example 5 of JP-A Nos. 6,871,887 and JP-A-2-96131 and JP-A-59-48753 are preferred dyes. Examples can be given. These sensitizing dyes may be used alone or in combination of two or more.

These sensitizing dyes can be added by the method described in paragraph No. 0106 of JP-A-11-119374, but it is not particularly limited to this method. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fog.
The amount is preferably 10 ^-6 to ¹ mol, more preferably 10 ^-4 to 10 ^-1 mol.

In the present invention, in order to improve the spectral sensitization efficiency,
Supersensitizers can be used. Strong color used in the present invention
As sensitizers, European Patent Publication EP587,338A
Gazette, U.S. Pat. No. 3,877,943,
No. 4,873,184;
Heteroaromatic or aliphatic mercapto compound, heteroaromatic
Group disulfide compounds, stilbene, hydrazine, tri
And a compound selected from azine. Especially good
A preferred supersensitizer is disclosed in JP-A-5-341432.
Disclosed heteroaromatic mercapto compounds, heteroaromatics
Group disulfide compounds, JP-A-4-18239
A compound represented by the general formula (I) or (II),
It is represented by the general formula (I) of Kaihei 10-111543.
Stilbene compound, JP-A-11-109547
Is a compound represented by the general formula (I). In particular
Conversion of M-1 to M-24 in JP-A-5-341432
Compounds, d-1) to d- of JP-A-4-18239.
14) The compound of S) described in JP-A-10-111543.
Compounds of S-01 to SS-07, JP-A-11-1095
No. 47, 31, 32, 37, 38, 41-45, 5
1 to 53 compounds. Addition amount of these supersensitizers
Is 10 per mol of silver halide in the emulsion layer. ^-Four~ 1
mol is preferable, per mol of silver halide
The range of 0.001 to 0.3 mol is more preferable.

In the photothermographic material of the present invention, it is particularly preferable to use, as the phosphorus-containing compound, an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acids (salts) and the like can be mentioned. Particularly preferred acids and salts thereof formed by hydration of diphosphorus pentoxide include orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, ammonium hexametaphosphate and the like. The acid or salt thereof formed by hydration of diphosphorus pentoxide, which can be preferably used in the present invention, is added to the image forming layer or the binder layer adjacent thereto in that a desired effect is exhibited in a small amount. The amount of the compound containing phosphorus and the acid or salt thereof formed by hydration of diphosphorus pentoxide (the amount of coating per m ^{2 of the} light-sensitive material) may be a desired amount according to the performance such as sensitivity and fog. .
1 to 500 mg / m ² is preferable, and 0.5 to 100 mg.
/ M ² is more preferred.

The photothermographic material of the present invention preferably contains a reducing agent for an organic silver salt. The reducing agent for the organic silver salt is any substance that reduces silver ions to metallic silver, preferably an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred. The reducing agent is used in an amount of 5 to 50 mol based on 1 mol of silver on the surface having the image forming layer.
It is preferably contained, more preferably 10 to 40 mol. The layer to which the reducing agent is added may be any layer on the image forming layer side with respect to the support. When added to a layer other than the image forming layer, 10 to 50 m per 1 mol of silver
It is preferable to use as much as ol. Further, the reducing agent may be a so-called precursor that is derivatized so as to function effectively only during development.

In the photothermographic material using an organic silver salt, a wide range of reducing agents can be used. For example,
JP-A-46-6074, JP-A-47-1238, JP-A-47-33621, JP-A-49-46427, JP-A-49-115540, and JP-A-50-1433.
No. 4, No. 50-36110, No. 50-147
Nos. 711 and 51-32632 and 51-1
JP-A Nos. 023721, 51-32324, and 5
1-51933, 52-84727, 55-108654, 56-146133, 57-82828, 57-82829, JP-A-6-3793, U.S.A. Patent No. 3,67
9,426, 3,751,252, 3,751,255, 3,763
Nos. 1,270, 3,782,949, 3,839,048, 3,92
Use of reducing agents disclosed in 8,686, 5,464,738, German Patent 2,321,328, European Patent Publication EP 692,732A, and the like. Can be. Amide oximes such as, for example, phenylamide oxime, 2-thienylamide oxime and p-phenoxyphenylamide oxime;
Azines such as, for example, 4-hydroxy-3,5-dimethoxybenzaldehyde azine; aliphatic carboxylic acid arylhydrazides such as a combination of 2,2′-bis (hydroxymethyl) propionyl-β-phenylhydrazine and ascorbic acid and ascorbic acid A combination of polyhydroxybenzene with hydroxylamine, reductone and / or hydrazine (for example, a combination of hydroquinone with bis (ethoxyethyl) hydroxylamine, piperidinohexose reductone or formyl-4-methylphenylhydrazine, etc. ); Hydroxamic acids such as phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; combinations of azines with sulfonamidophenols (eg, phenothiazine 2,6-dichloro-4-benzenesulfonamidophenol); α-cyanophenylacetic acid derivatives such as ethyl-α-cyano-2-methylphenylacetate and ethyl-α-cyanophenylacetate; 2,2′-dihydroxy- 1,1′-binaphthyl, 6,6′-dibromo-2,2′-dihydroxy-
1,1′-Binaphthyl and bis (2-hydroxy-1
Bis-β-naphthol as exemplified by -naphthyl) methane; of bis-β-naphthol and 1,3-dihydroxybenzene derivatives (such as 2,4-dihydroxybenzophenone or 2 ′, 4′-dihydroxyacetophenone). 5-pyrazolone such as 3-methyl-1-phenyl-5-pyrazolone; dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone, as exemplified in the combination; Reducton; 2,6
A sulfonamide phenol reducing agent such as dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-
1,2-dione and the like; 2,2-dimethyl-7-tert
Chromans such as -butyl-6-hydroxychroman;
2,6-dimethoxy-3,5-dicarbethoxy-1,
1,4-dihydropyridines such as 4-dihydropyridine; bisphenols (for example, bis (2-hydroxy-
3-tert-butyl-5-methylphenyl) methane,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 4,4-ethylidene-bis (2-tert-
Butyl-6-methylphenol), 1,1, -bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
5-trimethylhexane and 2,2-bis (3,5-
Dimethyl-4-hydroxyphenyl) propane, etc.);
Ascorbic acid derivatives (eg, 1-ascorbyl palmitate, ascorbyl stearate, etc.); and aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indane-1,3
-Dione; chromanol (such as tocopherol). Particularly preferred reducing agents are bisphenol, chromanol.

When a reducing agent is used in the present invention, it may be added by any method such as an aqueous solution, an organic solvent solution, a powder, a solid fine particle dispersion, and an emulsified dispersion. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

When an additive known as a “toning agent” for improving an image is included, the optical density may increase.
The toning agent may also be advantageous in forming a black silver image. The color tone agent is preferably contained in the layer on the image forming layer side with respect to the support in an amount of 0.1 to 50 mol per 1 mol of silver, more preferably 0.5 to 20 mol. Further, the toning agent may be a so-called precursor which is derivatized so as to function effectively only during development. In a photothermographic material using an organic silver salt, a wide range of color toning agents can be used. For example, JP-A-46-6077, JP-A-47-10282, JP-A-49-5019, JP-A-49-5020, JP-A-49-91215, JP-A-49-91215, and JP-A-50-2524 No. 50-32927, No. 50-67132, No. 50-67641
JP-A-50-114217, JP-A-51-322
No. 3, No. 51-27923, No. 52-147
Nos. 88, 52-99813 and 53-10
No. 20, No. 53-76020, No. 54-15
Nos. 6524, 54-156525, 61
183,642, JP-A-4-56848,
JP-B-49-10727, JP-B-54-20333, U.S. Pat. Nos. 3,080,254, 3,446,648, and 3,782,941.
No. 4,123,282, No. 4,123,282
No. 510,236, British Patent 1,380,79
No. 5, Belgian Patent No. 841,910 and the like can be used. Specific examples of the toning agent include phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one,
And cyclic imides such as quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione; naphthalimides (eg, N-hydroxy-1,8-naphthalimide) A) cobalt complex (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,
2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4
-Triazole and 2,5-dimercapto-1,3,
Mercaptans exemplified by 4-thiadiazole; N-
(Aminomethyl) aryldicarboximides, such as (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-
2,3-dicarboximide); and blocked pyrazoles, isothiuronium derivatives, and certain photobleaching agents (eg, N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1,8 −
(3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) -benzothiazole; and 3-ethyl-5-[(3-ethyl-2-benzothiazolinylidene)
-1-methylethylidene] -2-thio-2,4-oxazolidinedione; phthalazinone, a phthalazinone derivative or metal salt, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone And derivatives thereof such as 2,3-dihydro-1,4-phthalazinedione; combinations of phthalazinone with phthalic acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; Phthalazine, phthalazine derivative (for example, 4-
(1-naphthyl) phthalazine, 6-chlorophthalazine,
Derivatives such as 5,7-dimethoxyphthalazine, 6-isobutylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine, and 2,3-dihydrophthalazine) or metal salts; phthalazine and its derivatives And phthalic acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinedione, benzoxazine or naphthoxazine derivatives; Rhodium complexes that also function as a source of halide ions for silver halide formation, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and peroxides Sulfates, for example, peracids Disulfide ammonium and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-
Methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-
Benzoxazine-2,4-diones such as diones; pyrimidines and asymmetric-triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil, and tetraazapentalene derivatives (eg, 3,6-dimercapto-1,4-
Diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene and 1,4-di (o-chlorophenyl) -3,6-dimercapto-1H, 4H-2,3a,
5,6a-tetraazapentalene) and the like.

In the present invention, as a color tone agent, JP-A-2000-
Phthalazine derivatives represented by the general formula (F) described in JP-A-35631 are preferably used. Specifically, A-1 to A-10 described in the publication are preferably used.

The color-toning agent may be added by any method such as a solution, a powder and a solid fine particle dispersion. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

In the photothermographic material of the present invention, the silver halide emulsion and / or the organic silver salt may contain an antifoggant,
Stabilizers and stabilizer precursors can further protect against the formation of additional fog and stabilize against reduced sensitivity during inventory storage. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are described in US Pat. No. 2,131,03.
No. 8, No. 2,694,716, azaindenes described in U.S. Pat. Nos. 2,886,437 and 2,444,605, U.S. Pat. No. 2,728,663, mercury salts described in U.S. Pat. No. 3,287,135, urazole described in U.S. Pat. No. 3,287,135, U.S. Pat. No. 3,235,652.
Patent No. 62, UK Patent No. 62
Oxime, nitrone, nitroindazole described in US Pat. No. 3,448, polyvalent metal salt described in US Pat. No. 2,839,405, US Pat. No. 3,220,839.
No. 2,566,263 and U.S. Pat. No. 2,597,9.
15, palladium, platinum and gold salts; U.S. Pat. Nos. 4,108,665 and 4,4;
No. 4,128,557 and U.S. Pat. Nos. 4,137,079 and 4,138,365.
And the phosphorus compounds described in U.S. Pat. No. 4,411,985.

The photothermographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acid used in the present invention may be any benzoic acid derivative, but a preferred example is described in US Pat.
No. 939, No. 4,152,160, JP-A-9-329863, JP-A-9-329864, and JP-A-9-281637. The benzoic acid may be added to any layer of the photothermographic material, but is preferably added to the layer on the image forming layer side with respect to the support, more preferably to the organic silver salt-containing layer. The addition of benzoic acids may be performed at any step in the preparation of the coating solution, and when the benzoic acid is added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be performed, but the coating is performed after the preparation of the organic silver salt. Immediately before is preferred.
The benzoic acid may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent, and a color tone agent. The benzoic acid may be added in any amount, but may be 1 × 10 ⁻⁶ mol to 2 mol per mol of silver.
1 is preferable, and 1 × 10 ⁻³ mol to 0.5 mol is more preferable.

Although not essential for practicing the present invention,
Mercury (II) salt was added to the image forming layer as an antifoggant
May be advantageous. Preferred for this purpose
Mercury (II) salts are mercury acetate and mercury bromide. Book
The added amount of mercury used in the present invention is as follows.
preferably 1 × 10 per mol^-9mol ~ 1 × 10 ^-3
mol, more preferably 1 × 10^-8mol ~ 1 × 10
^-Fourmol range.

Further, Japanese Patent Application Laid-Open No. 2000-284399
The salicylic acid derivative represented by the formula (Z) described in
It is preferably used as an inhibitor. Specifically, the gazette
(A-1) to (A-60) described in are preferably used.
You. The amount of the salicylic acid derivative represented by the formula (Z) is:
Mol amount per mol Ag (mol / mol Ag)
, Preferably 1 × 10^-Five~ 5 × 10^-1mol /
molAg, more preferably 5 × 10^-Five~ 1 × 10^-1m
ol / mol Ag, more preferably 1 × 10 ^-Four~ 5x
10^-2mol / mol Ag. These are only one kind
They may be used alone or in combination of two or more.

As the antifoggant preferably used in the present invention, formalin scavenger is effective.
1) to (S-24).

The antifoggant used in the present invention may be water or a suitable organic solvent such as alcohols (methanol,
It can be used by dissolving in ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. In addition, dibutyl phthalate,
Oils such as tricresyl phosphate, glyceryl triacetate or diethyl phthalate, dissolved using an auxiliary solvent such as ethyl acetate or cyclohexanone,
An emulsified dispersion can be prepared and used mechanically. Alternatively, the powder can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Menton-Gaulin, a microfluidizer or an ultrasonic wave by a method known as a solid dispersion method.

The antifoggant used in the present invention may be added to the layer on the image forming layer side with respect to the support, that is, to the image forming layer or any other layer on this layer side. Preferably, it is added to an adjacent layer. The image forming layer is a layer containing a reducible silver salt (organic silver salt), and is preferably an image forming layer further containing a photosensitive silver halide.

The photothermographic material of the present invention contains a mercapto compound, a disulfide compound, and a thione compound for the purpose of controlling or suppressing the development by controlling or accelerating the development, and improving the storability before and after the development. Can be. When a mercapto compound is used in the present invention, any structure may be used, but Ar-SM, Ar
Those represented by -SS-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring or a condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring can be, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, having one or more carbon atoms, preferably 1-4 carbon atoms), alkoxy ( For example, it may have a substituent selected from the group consisting of one or more carbon atoms, preferably those having 1 to 4 carbon atoms, and aryl (which may have a substituent). Good. Examples of the mercapto-substituted heteroaromatic compound include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole,
6-ethoxy-2-mercaptobenzothiazole, 2,
2'-dithiobis- (benzothiazole), 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2- Mercaptoquinoline, 8-mercaptopurine,
2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5
6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto- 1,2,
4-triazole, 4-hydrokilocy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-
Methyl pyrimidine hydrochloride, 3-mercapto-5
-Phenyl-1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, sodium 3- (5-mercaptotetrazole) -benzenesulfonate, N-
Methyl-N '-{3- (5-mercaptotetrazolyl)
Examples include phenyl diurea and 2-mercapto-4-phenyloxazole, but the present invention is not limited thereto. The addition amount of these mercapto compounds is 0.001 to 1.0 mol per mol of silver in the image forming layer.
1 is preferable, and more preferably, 1 mol of silver
0.001 to 0.3 mol per unit.

In the photothermographic material of the present invention, a volatile base such as ammonia is easily volatilized, and is volatilized not only during a coating step or during heat development but also during storage. Undesirably, the NH ₄ ⁺ content is 1 m of support
It is preferable that the coating amount per ² is 0.06 mmol or less. More preferably, it is 0.03 mmol or less. The amount of NH ₄ ⁺ in the membrane was determined by using Tosoh's 8000 type ion chromatograph (electric conductivity method) and Tosoh's TSKgel IC-Cation as a separation column and a TSK guard column IC-C as a guard column. It measured using. As the eluent, a 2 mM nitric acid aqueous solution was used, and 1.2 ml
/ Min flow rate. The temperature of the column bath is 4
Performed at 0 ° C. For the extraction of NH ₄ ⁺ from the photosensitive material, a mixed solution of acetic acid and ion-exchanged water = 1: 148 was used as an extract, and a photosensitive material having a size of 1 × 3.5 cm ² was immersed in 5 ml of the extract for 2 hours. And after extraction, 0.45
The solution filtered through a μm filter was measured. Membrane pH
It is preferable to use an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a nonvolatile base.
The film surface pH of the photothermographic material of the present invention before the heat development processing is preferably 6.0 or less, more preferably 5.5 or less. There is no particular lower limit, but 3
It is about. The method of measuring the film surface pH is described in JP-A-200
No. 0-284339, paragraph No. 0123.

The photothermographic material of the present invention is provided on a support.
It is preferable that the image forming layer has an image forming layer containing an organic silver salt, a reducing agent and a photosensitive silver halide, and at least one protective layer is provided on the image forming layer. The photothermographic material of the invention preferably has at least one back layer on the side opposite to the image forming layer (back surface) with respect to the support.

Examples of the binder used in the present invention include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as gelatin, gum arabic, poly (vinyl alcohol), hydroxyethylcellulose, cellulose acetate, and cellulose acetate butyrate. , Poly (vinylpyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile) ), Copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethane) s, phenoxy resins, poly (vinyl chloride) Den), poly (epoxides),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides).

[0095] Although it may be hydrophilic or hydrophobic, in the present invention, it is preferable to use a hydrophobic transparent binder in order to reduce fog after thermal development. Preferred binders include polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, polyurethane and the like. Among them, polyvinyl butyral, cellulose acetate, and cellulose acetate butyrate are particularly preferably used.

In order to protect the surface of the light-sensitive material and prevent abrasion, a protective layer may be provided outside the image forming layer. The binder used for these protective layers may be the same or different from the binder used for the image forming layer. Usually, a polymer having a higher softening point than the binder polymer constituting the image forming layer is used to prevent abrasion, phase deformation, and the like, and cellulose acetate, cellulose acetate butyrate, and the like are suitable for this purpose.

In the case of applying a solvent (dispersion medium) containing water as a main component as the binder used in the present invention, it is preferable to use the following polymer latex. At least one of the image forming layers containing the photosensitive silver halide of the photothermographic material of the present invention contains at least 50% by weight of the total binder of the polymer latex described below.
The image forming layer used above is preferable. Further, the polymer latex may be used not only for the image forming layer but also for the protective layer and the back layer. In particular, when the photothermographic material of the present invention is used for printing in which dimensional change is problematic, the protective layer or the back layer It is preferable to use a polymer latex also for the layer. However, the "polymer latex" referred to here is a polymer in which a water-insoluble hydrophobic polymer is dispersed as fine particles in a water-soluble dispersion medium. The dispersion state is such that the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or partially dispersed in polymer molecules and the molecular chains themselves are molecularly dispersed. Any of them may be used. The polymer latex used in the present invention is described in "Synthetic Resin Emulsion (Taira Okuda, edited by Hiroshi Inagaki, published by Kobunshi Kankokai (197
8))), "Applications of Synthetic Latex (Edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Polymer Publishing Association (19)
93)) "," Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970)) "and the like. The average particle size of the dispersed particles is preferably in the range of about 1 to 50,000 nm, more preferably about 5 to 1,000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

The polymer latex used in the present invention may be a so-called core / shell type latex other than a polymer latex having a normal uniform structure. In this case, it may be preferable to change the glass transition temperature of the core and the shell.

The glass transition temperature (Tg) of the polymer latex preferably used for the binder used in the present invention differs between the protective layer, the back layer and the image forming layer. In the image forming layer, the temperature is preferably from -30 to 40 ° C. in order to promote diffusion of the photographically useful material during thermal development.
When used for the protective layer or the back layer, a glass transition temperature of 25 to 70 ° C. is preferable for contacting various devices.

The minimum film forming temperature (MFT) of the polymer latex used in the present invention is preferably from -30 ° C to 90 ° C, more preferably from about 0 ° C to 70 ° C. A film-forming aid may be added to control the minimum film-forming temperature. The film forming aid is an organic compound (usually an organic solvent) which is also called a plasticizer and lowers the minimum film forming temperature of the polymer latex. For example, the above-mentioned "Synthetic Latex Chemistry (Souichi Muroi, published by Kobunshi Kankokai (1970)") )"It is described in.

The polymer species used in the polymer latex used in the present invention include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. And the like.
The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The number average molecular weight of the polymer is preferably 5,000 to 1,000,000, and more preferably 10,000 to 100,000. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

Specific examples of the polymer latex used as a binder for the image forming layer of the photothermographic material of the present invention include methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate / butadiene / itaconic acid copolymer latex. Latex of ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer, latex of styrene / butadiene / acrylic acid copolymer, latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer, methyl Latex of methacrylate / vinyl chloride / acrylic acid copolymer, vinylidene chloride / ethyl acrylate / acrylonitrile / Such as latex of methacrylic acid copolymers. More specifically, methyl methacrylate / ethyl acrylate / methacrylic acid = 33.5.
/50/16.5 (wt%) copolymer latex,
Methyl methacrylate / butadiene / itaconic acid = 4
A copolymer latex of 7.5 / 47.5 / 5 (% by weight), a copolymer latex of ethyl acrylate / methacrylic acid = 95/5 (% by weight), and the like can be given. Such polymers are also commercially available, for example, Sebian A-4635,465 as an example of an acrylic resin.
83, 4601 (all manufactured by Daicel Chemical Industries, Ltd.), N
ipol LX811, 814, 821, 820, 85
7 (all made by Nippon Zeon Co., Ltd.), VONCORT-R3
As polyester resins such as 340, R3360, R3370, 4280 (all manufactured by Dainippon Ink and Chemicals, Inc.), FINETEX ES650, 611, 675, 8
50 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-siz
e, WMS (all manufactured by Eastman Chemical Co., Ltd.) such as HYDRAN AP10, 20,
Rubber-based resins such as 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.) include LACSTAR 7310K, 330
7B, 4700H, 7132C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol LX410, 430, 43
5, 438C (manufactured by Nippon Zeon Co., Ltd.), vinyl chloride resins such as G351 and G576 (manufactured by Nippon Zeon Co., Ltd.), and vinylidene chloride resin, L50
2, L513 (all manufactured by Asahi Kasei Corporation), Aron D7
020, D504, D5071 (Mitsui Toatsu Co., Ltd.
Chemical Pearl S12 as an olefin resin
0, SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.) and the like. These polymers may be used alone or as a mixture of two or more as necessary.

The image forming layer contains 50% by weight of the total binder.
As the above, the above-mentioned polymer latex is preferably used, and it is more preferable to use the above-mentioned polymer latex as 70% by weight or more.

If necessary, hydrophilic polymers such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, and hydroxypropylmethylcellulose may be added to the image forming layer in a range of 50% by weight or less of the whole binder. . The amount of the hydrophilic polymer to be added is preferably 30% by weight or less, more preferably 15% by weight or less of the total binder in the image forming layer.

The image forming layer is preferably prepared by applying an aqueous coating solution and then drying. However, the term "aqueous" as used herein means that 60% by weight or more of the solvent (dispersion medium) of the coating liquid is water. Components other than water in the coating solution are methyl alcohol, ethyl alcohol, isopropyl alcohol,
Water-miscible organic solvents such as methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 90/10,
Water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 80/15/5, water / methanol / dimethylformamide = 90/5/5. (However, the numbers represent weight%.)

The total amount of binder in the image forming layer is 0.2 to 3
0 g / m ^2, more preferably in the range of 1 to 15 g / m ^2. A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

Further, as a binder for the protective layer, JP-A-2000-267226, paragraphs [0025] to [0025]
A combination of polymer latexes having different I / O values obtained by dividing an inorganic value by an organic value based on the organic conceptual diagram described in 0029 can be preferably used.

In the present invention, if necessary,
Nos. 00-267226, Paragraph Nos. 0021-002
5 plasticizer (eg, benzyl alcohol, 2,2,
Addition of 4-trimethylpentanediol-1,3-monoisobutyrate) can control the film formation temperature. Further, as described in Paragraph Nos. 0027 to 0028 of JP-A-2000-267226, a hydrophilic polymer may be added to a polymer binder, and a water-miscible organic solvent may be added to a coating solution.

Each layer is described in JP-A-2000-196.
No. 783, using a first polymer latex having a functional group introduced therein and a crosslinking agent having a functional group capable of reacting with the first polymer latex and / or a second polymer latex. You can also. The functional group is a carboxyl group, a hydroxyl group, an isocyanate group, an epoxy group, an N-methylol group, an oxazolinyl group, and the like.As a crosslinking agent, an epoxy compound, an isocyanate compound, a blocked isocyanate compound, a methylol compound, a hydroxy compound, It is selected from a carboxyl compound, an amino compound, an ethyleneimine compound, an aldehyde compound, a halogen compound and the like. Specific examples of the cross-linking agent include hexamethylene isocyanate and duranate WB4 as isocyanate compounds.
0-80D, WX-1741 (manufactured by Asahi Kasei Corporation),
Bayhijur 3100 (Sumitomo Bayer Urethane Co., Ltd.)
Manufactured), Takenate WD725 (Takeda Pharmaceutical Co., Ltd.)
100, 200 (manufactured by Nippon Polyurethane Co., Ltd.), water-dispersible polyisocyanate described in JP-A-9-160172; Sumitex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.) as an amino compound Denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.) as an epoxy compound; 2,4-dichloro- as a halogen compound
6-hydroxy-1,3,5-triazine sodium and the like.

The total amount of the binder for the image forming layer is from 0.2 to
30 g / m ^2, more preferably in the range of 1.0~15g / m ^2. The total amount of the binder for the protective layer is from 1 to 10.0 g / m ² , more preferably from ^{2 to} 10.0 g / m ² , necessary for achieving a film thickness of 3 μm or more preferably used in the present invention.
The range is preferably from 6.0 g / m ^{2 to} 6.0 g / m ² . The thickness of the protective layer preferably used in the present invention is 3 μm or more,
μm or more is more preferable. The upper limit of the thickness of the protective layer is not particularly limited, but is preferably 10 μm or less, more preferably 8 μm or less in consideration of coating and drying. The total amount of the binder for the back layer is preferably in the range of 0.01 to 10.0 g / m ² , more preferably 0.05 to 5.0 g / m ² .

Each of these layers may be provided in two or more layers. When the image forming layer has two or more layers, it is preferable to use a polymer latex as a binder for all the layers. Further, the protective layer is a layer provided on the image forming layer, and may have two or more layers.
Preferably, a polymer latex is used for the layer, especially the outermost protective layer. The back layer is a layer provided on the undercoat layer on the back surface of the support, and there may be two or more layers. However, it is preferable to use a polymer latex for at least one layer, particularly the outermost back layer.

As used herein, the term "slip agent" means a compound which reduces the coefficient of friction of the surface of an object when present on the surface of the object as compared with the case where it is not present. The type is not particularly limited.

As the slipping agent used in the present invention, JP-A-1
Paragraph Nos. 0061 to 0064 of 1-84573,
Paragraph No. 0049 of JP-A-2000-47083
Compounds described in 0062 can be mentioned. Specific examples of preferred slip agents include Cellolsol 524 (main component carnauba wax), Polylon A, 393, H-481.
(Main component polyethylene wax), high micron G-1
10 (main component ethylene bisstearic amide), Himicron G-270 (main component stearic amide)
(Above, Chukyo Yushi Co.), etc. _{W-1 C 16 H 33 -O} -SO 3 Na W-2 C 18 H 37 -O-SO 3 Na and the like. The amount of the slip agent used is 0.1 to 50% by weight of the binder amount of the added layer, preferably 0.5 to 50% by weight.
30% by weight.

In the present invention, JP-A-2000-1719
No. 35, as described in JP-A-2000-47083, the preheating unit is conveyed by an opposing roller, and the heat development processing unit drives the roller having the image forming layer on the side having the image forming layer so that the back surface on the opposite side is rotated. In the case of using a heat development processing apparatus which conveys the heat-developable image recording material by sliding it on a smooth surface, the ratio of the friction coefficient between the outermost surface layer of the heat-developable image recording material having the image forming layer and the outermost surface layer of the back surface at the development processing temperature is as follows. , 1.5 or more,
The upper limit is not particularly limited, but is about 30. Also, μ
b is 1.0 or less, preferably 0.05 to 0.8.
This value is obtained by the following equation. Ratio of friction coefficient = dynamic friction coefficient (μe) between the roller member of the heat developing machine and the surface having the image forming layer / dynamic friction coefficient (μb) between the smooth surface member and the back surface of the heat developing machine (heat development processing temperature) The sliding property of the outermost layer on the surface having the heat-development processing machine member and the image forming layer and / or the opposite surface thereof can be adjusted by including a slipping agent in the outermost layer and changing the amount of addition. it can.

On both sides of the support, JP-A-64-2054
4, JP-A-1-180537, JP-A-1-18037
No. 209443, JP-A-1-285939,
JP-A-1-296243, JP-A-2-24649
JP, JP-A-2-24648, JP-A-2-18-18
4844, JP-A-3-109545, JP-A-3-137637, JP-A-3-141346, JP-A-3-141347, JP-A-4-96
No. 055, U.S. Pat. No. 4,645,731, JP-A-4-68344, and Japanese Patent No. 2,557,
No. 641, page 2, right column, line 20 to page 3, right column, line 30;
Paragraph No. 0020 of JP-A-2000-39684
[0037] It is preferable to provide an undercoat layer containing a vinylidene chloride copolymer containing 70% by weight or more of a vinylidene chloride monomer repeating unit described in paragraphs [0063] to [0080] of JP-A-2000-47083.

When the amount of the vinylidene chloride monomer is less than 70% by weight, sufficient moisture-proof properties cannot be obtained, and the dimensional change over time after thermal development becomes large. Further, the vinylidene chloride copolymer preferably contains a repeating unit of a carboxyl group-containing vinyl monomer as another constituent repeating unit of the vinylidene chloride monomer. It is only vinyl chloride monomer that contains such a repeating unit,
The polymer (polymer) crystallizes, making it difficult to form a uniform film when applying a moisture-proof layer, and a carboxyl group-containing vinyl monomer is indispensable for stabilizing the polymer (polymer). Because there is. The molecular weight of the vinylidene chloride copolymer used in the present invention is 450,000 in weight average molecular weight.
00 or less, more preferably 10,000 to 45,000. When the molecular weight is increased, the adhesiveness between the vinylidene chloride copolymer layer and a support layer such as polyester tends to deteriorate.

The content of the vinylidene chloride copolymer used in the present invention is 0.3 μm or more as a total film thickness per one side of the undercoat layer containing the vinylidene chloride copolymer.
Preferably, it is in the range of 0.3 μm to 4 μm.

The vinylidene chloride copolymer layer as the undercoat layer is preferably provided as the first undercoat layer directly provided on the support. Usually, one layer is provided on each side. May be provided in two or more layers.
When a multilayer structure having two or more layers is used, the total amount of the vinylidene chloride copolymer may be within the range of the present invention.
Such a layer may contain a crosslinking agent, a matting agent, and the like in addition to the vinylidene chloride copolymer.

The support may be coated with an undercoat layer using SBR, polyester, gelatin or the like as a binder, if necessary, in addition to the vinylidene chloride copolymer layer. These undercoat layers may have a multilayer structure or may be provided on one side or both sides of the support. The thickness of the undercoat layer (per layer) is generally 0.01 to 5 μm, more preferably 0.1 to 5 μm.
05 to 1 μm.

Various supports can be used for the photothermographic material of the present invention. Typical supports include polyesters such as polyethylene terephthalate and polyethylene naphthalate, cellulose nitrate, cellulose esters, polyvinyl acetal, syndiotactic polystyrene, polycarbonate, and paper supports coated on both sides with polyethylene. Of these, biaxially stretched polyester, particularly polyethylene terephthalate (PET), is preferred in terms of strength, dimensional stability, chemical resistance and the like. The thickness of the support is preferably 90 to 180 μm as a base thickness excluding the undercoat layer.

As the support used for the photothermographic material of the present invention, JP-A-10-48772 and JP-A-10-87772
10676, JP-A-10-10677, JP-A-11-65025, JP-A-11-13864
No. 8, polyester which has been subjected to a heat treatment in a temperature range of 130 to 185 ° C. in order to alleviate internal strain remaining in the film at the time of biaxial stretching and eliminate heat shrinkage strain generated during thermal development processing. Particularly, polyethylene terephthalate is preferably used.

The support 12 after such heat treatment was used.
The dimensional change rate by heating at 0 ° C. for 30 seconds is −0.03% to + 0.01% in the vertical direction (MD), and 0 in the horizontal direction (TD).
Preferably, it is 0.04%.

The photothermographic material of the present invention has been disclosed in JP-A No. 11-84573, paragraphs 0040 to 0051, for the purpose of reducing dust adhesion, preventing the occurrence of static marks, and preventing defective transport in the automatic transport step. Can be prevented by using the conductive metal oxide and / or the fluorine-based surfactant described in (1). As the conductive metal oxide, US Pat. No. 5,575,957, JP-A-11-22
Needle-like conductive tin oxide doped with antimony described in paragraphs 0012 to 0020 of JP-A-3901 and fibrous tin oxide doped with antimony described in JP-A-4-29134 are preferably used.

The surface specific resistance (surface resistivity) of the metal oxide-containing layer is 10 ¹² Ω or less, preferably 10 ¹¹ Ω or less in an atmosphere at 25 ° C. and a relative humidity of 20%. Thereby, good antistatic properties can be obtained. The lower limit of the surface resistivity at this time is not particularly limited, but is usually about 10 ⁷ Ω.

The Beck smoothness of at least one of the surface having the image forming layer of the photothermographic material of the invention and the outermost layer surface opposite to the surface, and preferably both, is 2,000 seconds or less, and more preferably 10 seconds or less. 2000 seconds. The Beck smoothness in the present invention is based on Japanese Industrial Standard (JIS).
It can be easily obtained according to P8119 “Smoothness test method of paper and paperboard with Beck tester” and TAPPI standard method T479. The Beck smoothness of the outermost layer on the surface having the image forming layer of the photothermographic material and the outermost layer on the opposite side are described in paragraph No. 00 of JP-A-11-84573.
As described in 52 to 0059, it can be controlled by appropriately changing the particle size and the amount of the matting agent contained in the layers on both surfaces.

In the present invention, a water-soluble polymer is preferably used as a thickener for imparting coatability, and may be a natural product or a synthetic polymer, and the type thereof is not particularly limited. Specifically, as natural products, starches (corn starch,
Starch, etc.), seaweed (agar, sodium alginate, etc.), vegetable glue (gum arabic, etc.), animal protein (glue, casein, gelatin, egg white, etc.), fermented glue (pullulane, dextrin, etc.), etc. Semi-synthetic polymers such as starchy materials (soluble starch, carboxyl starch, dextran, etc.) and celluloses (viscose, methylcellulose, ethylcellulose,
Carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc.), and synthetic polymers (polyvinyl alcohol, polyacrylamide,
Polyvinyl pyrrolidone, polyethylene glycol, polypropylene glycol, polyvinyl ether, polyethylene imine, polystyrene sulfonic acid or its copolymer, polyvinyl sulfanic acid or its copolymer, polyacrylic acid or its copolymer, acrylic acid or its copolymer Maleic acid copolymer, maleic acid monoester copolymer, acryloylmethylpropanesulfonic acid or a copolymer thereof).

Among these, the water-soluble polymers preferably used include sodium alginate, gelatin, dextran, dextrin, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol, Examples thereof include polystyrenesulfonic acid or its copolymer, polyacrylic acid or its copolymer, maleic acid monoester copolymer, acryloylmethylpropanesulfonic acid or its copolymer, and particularly preferably used as a thickener.

Among these, particularly preferred thickeners include
Examples include gelatin, dextran, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polystyrenesulfonic acid or a copolymer thereof, polyacrylic acid or a copolymer thereof, and a maleic acid monoester copolymer. These compounds are
It is described in detail in "Applications and Markets of New Water-Soluble Polymers" (published by CMC Corporation, edited by Shinji Nagatomo, issued on November 4, 1988).

The amount of the water-soluble polymer used as a thickener is not particularly limited as long as the viscosity increases when added to a coating solution. Generally, the concentration in the liquid is 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, and particularly preferably 0.1 to 10% by mass. The viscosity obtained by these methods is 1 to 200 mPa as an increase from the initial viscosity.
S is preferable, and more preferably 5 to 100 mPa · s.
It is. The viscosity is a value measured at 25 ° C. with a B-type rotational viscometer. When adding to a coating solution or the like, it is generally desirable to add the thickener in a solution as dilute as possible. In addition, it is preferable to perform sufficient stirring during addition.

The surfactant used in the present invention will be described below. Surfactants used in the present invention are classified into dispersants, coating agents, wetting agents, antistatic agents, photographic control agents, and the like depending on the purpose of use, and the surfactants described below are appropriately selected and used. These objectives can be achieved by doing so. The surfactant used in the present invention may be either nonionic or ionic (anion, cation, betaine). Further, a fluorine-based surfactant is also preferably used.

Preferred nonionic surfactants include:
Polyoxyethylene, polyoxypropylene, polyoxybutylene, polyglycidyl and a surfactant having a nonionic hydrophilic group of sorbitan can be mentioned. Specifically, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether , Polyoxyethylene-polyoxypropylene glycol, polyhydric alcohol fatty acid partial ester, polyoxyethylene polyhydric alcohol fatty acid partial ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, fatty acid diethanolamide, and triethanolamine fatty acid partial ester. be able to.

Examples of the anionic surfactant include a carboxylate, a sulfate, a sulfonate and a phosphate ester. Representative examples thereof include a fatty acid salt, an alkylbenzene sulfonate and an alkylnaphthalenesulfonic acid. Salt, alkyl sulfonate, α-olefin sulfonate, dialkyl sulfosuccinate, α-sulfonated fatty acid salt, N-methyl-N-oleyltaurine, petroleum sulfonate, alkyl sulfate, sulfated oil, polyoxy Examples include ethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene styrenated phenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, and naphthalene sulfonate formaldehyde condensate. Can be.

As the cationic surfactant, an amine salt,
Examples thereof include quaternary ammonium salts and pyridium salts, and include primary to tertiary fatty amine salts and quaternary ammonium salts (tetraalkylammonium salts, trialkylbenzylammonium salts, alkylpyridium salts, alkylimidazolium salts and the like). ).

Examples of the betaine-based surfactant include carboxybetaine and sulfobetaine.
-Trialkyl-N-carboxymethylammonium betaine, N-trialkyl-N-sulfoalkyleneammonium betaine and the like.

These surfactants are described in "Application of Surfactants" (written by Koshobo and Takao Karimei, published on September 1, 1980).
It is described in. In the present invention, a preferred surfactant is not particularly limited in its use amount, and any surfactant may be used as long as desired surfactant properties can be obtained. The amount of the fluorine-containing surfactant applied is 0.01 mg / m ^{2 or} more.
250 mg is preferred.

Specific examples of the surfactant are described below, but are not limited thereto (here, -C ₆ H _4- represents a phenylene group). _{WA-1: C 16 H 33} (OCH 2 CH 2) 10 OH WA-2: C 9 H 19 -C 6 H 4 - (OCH 2 CH 2) 12 O
H WA-3: Sodium dodecylbenzenesulfonate WA-4: Sodium tri (isopropyl) naphthalenesulfonate WA-5: Sodium tri (isobutyl) naphthalenesulfonate WA-6: Sodium dodecyl sulfate WA-7: Di-α-sulfosuccinate (2-ethylhexyl) ester sodium salt _{WA-8: C 8 H 17} -C 6 H 4 - (CH 2 CH 2 O) 3 (C
_{H 2) 2 SO 3 K WA} -10: cetyltrimethylammonium chloride _{WA-11: C 11 H 23} CONHCH 2 CH 2 N (+) (C
^{_{H 3) 2 -CH 2 COO (}} -) WA-12: C 8 F 17 SO 2 N (C 3 H 7) (CH 2 CH 2
O) ₁₆ H WA-13: C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) CH ₂ COO
_{K WA-14: C 8 F} 17 SO 3 K WA-15: C 8 F 17 SO 2 N (C 3 H 7) (CH 2 CH 2
_{O) 4 (CH 2) 4} SO 3 Na WA-16: C 8 F 17 SO 2 N (C 3 H 7) (CH 2) 3 O
^{_{CH 2 CH 2 N (+)}} (CH 3) 3 -CH 3 · C 6 H 4 -SO 3 (-) WA-17: C 8 F 17 SO 2 N (C 3 H 7) CH 2 CH 2 C
H ₂ N ⁽⁺⁾ (CH ₃ ) ₂ —CH ₂ COO ⁽⁻⁾

In a preferred embodiment of the present invention, an intermediate layer may be provided, if necessary, in addition to the image forming layer and the protective layer. For the purpose of improving productivity and the like, it is preferable that these plural layers are simultaneously coated in an aqueous system. The coating method includes extrusion coating, slide bead coating, curtain coating, and the like.
The slide bead coating method shown in FIG.

In the case of a silver halide photographic light-sensitive material using gelatin as a main binder, it is rapidly cooled in a first drying zone provided downstream of a coating die, and as a result, gelatinization of gelatin occurs and the coating film is cooled. Is solidified. The coating film that has been cooled and solidified and has stopped flowing is guided to the subsequent second drying zone, where the solvent in the coating liquid is volatilized and formed into a film in the subsequent drying zone. As a drying method after the second drying zone, an air loop method in which a jet is blown from a U-shaped duct to a roller-supported support, or a support in which the support is wound around a cylindrical duct in a helical shape, and conveyed and dried. A fire method (air floating method) and the like can be mentioned.

When a layer is formed using a coating solution in which the main component of the binder is a polymer latex, the flow of the coating solution cannot be stopped by rapid cooling, so that only the first drying zone is insufficient for preliminary drying. In some cases.
In this case, in a drying method such as used in a silver halide photographic light-sensitive material, flow unevenness and drying unevenness occur, and a serious defect is easily generated on the coated surface.

The preferred drying method in the present invention is a horizontal drying method regardless of the first drying zone or the second drying zone described in JP-A-2000-002964, at least until the constant-rate drying is completed. This is a method of drying in a drying zone. The transfer of the support from the time immediately after the coating until the support is guided to the horizontal drying zone may or may not be horizontal, and the rising angle of the coating machine with respect to the horizontal direction may be between 0 and 70 °. In addition, the horizontal drying zone in the present invention only needs to be conveyed within ± 15 ° up and down with respect to the horizontal direction of the coating machine, and does not mean horizontal conveyance.

The constant-rate drying in the present invention means a drying process in which a liquid film temperature is constant and all the heat flowing in is used for evaporating the solvent. At the end of drying, the rate of drying decreases at the end of drying due to various factors (such as the rate of diffusion of the material inside the material that controls the movement of water and the retreat of the evaporation surface), and the applied heat is also used to raise the liquid film temperature. Drying process. The critical moisture content at which the transition from the constant rate process to the rate reduction process is 200-3
00%. When constant-rate drying is completed, drying proceeds sufficiently until the flow stops, and a drying method such as a silver halide photographic light-sensitive material can also be employed. It is preferred to dry in the horizontal drying zone to the drying point.

The drying conditions for forming the image forming layer and / or the protective layer are such that the liquid film surface temperature during constant rate drying is 3 to less than the minimum film forming temperature of polymer latex (MTF; usually the glass transition temperature Tg of polymer). (5 ° C. higher) or more. Normally 25 ° C to 40 ° C due to limitations of manufacturing equipment
Often. Further, the dry-bulb temperature during the rate-decreasing drying is preferably a temperature lower than the Tg of the support (usually 80 ° C. or lower in the case of PET). The liquid film surface temperature in this specification refers to the solvent liquid film surface temperature of the coating liquid film applied to the support, and the dry bulb temperature refers to the temperature of the drying air in the drying zone.

When drying is performed under conditions where the liquid film surface temperature during constant-rate drying is low, the drying tends to be insufficient. For this reason, particularly, the film forming property of the protective layer is significantly reduced, and cracks are easily generated on the film surface. In addition, the film strength is weakened, and serious problems such as susceptibility to scratches during transportation in an exposure machine or a heat developing machine are likely to occur.

On the other hand, when dried under the condition that the liquid film surface temperature becomes high, the protective layer mainly composed of the polymer latex quickly forms a film, while the lower layer such as the image forming layer has fluidity. Since it is not stopped, irregularities are likely to be generated on the surface. Further, when excessive heat higher than Tg is applied to the support (base), the dimensional stability and the curl resistance of the photosensitive material tend to deteriorate.

The same applies to the sequential coating in which the lower layer is coated and dried and then the upper layer is coated. In particular, the coating for performing the simultaneous multi-layer coating in which the upper layer is coated before the lower layer is dried and both layers are dried simultaneously. As for the liquid properties, the pH difference between the coating solution for the image forming layer and the coating solution for the protective layer is preferably 2.5 or less, and the smaller the pH difference, the more preferable. Coating solution pH
When the difference is large, micro-aggregation is likely to occur at the interface of the coating solution, and a serious surface failure such as a coating streak tends to occur during long continuous coating.

The viscosity of the coating liquid for the image forming layer is 15 to 25 ° C.
100 mPa · s is preferred, and more preferably 30 to
70 mPa · s. On the other hand, the coating liquid viscosity of the protective layer is 2
The temperature is preferably 5 to 75 mPa · s at 5 ° C., more preferably 20 to 50 mPa · s. These viscosities are measured by a B-type viscometer.

Winding after drying is preferably carried out under the conditions of a temperature of 20 to 30 ° C. and a relative humidity of 45 ± 20%. Good or inside. Further, when the processing form is a roll product, it is also preferable to adopt a roll form wound on the side opposite to the winding form at the time of processing in order to remove the curl generated in the winding form. The relative humidity of the photosensitive material is 20 to
It is preferable that the temperature be controlled in the range of 55% (measured at 25 ° C.).

In a conventional photographic emulsion coating solution which is a viscous solution containing a silver halide and containing a silver halide, bubbles are dissolved and disappear in the solution simply by sending the solution under pressure. Even when returned, there is almost no bubble deposition. However, in the case of an image forming layer coating solution containing an organic silver salt dispersion and a polymer latex which are preferably used in the present invention, defoaming tends to be insufficient only by pressurized liquid feeding, so that a gas-liquid interface does not occur. It is preferable to remove the bubbles by applying ultrasonic vibration while feeding the liquid.

In the present invention, the defoaming of the coating solution is performed by deaeration under reduced pressure before the coating solution is applied, and further, 1.5 kg / cm ^2.
It is preferable to apply the ultrasonic vibration while continuously feeding the liquid while maintaining the above-mentioned pressurized state and avoiding the gas-liquid interface. Specifically, Japanese Patent Publication No. 55-6405 (4)
The method described on page 20, line 7 to page 7, line 11) is preferred. As an apparatus for performing such defoaming, JP-A-2000-
The apparatus shown in the embodiment of JP-A-98534 and the apparatus shown in FIG. 3 can be preferably used.

The pressure condition is preferably 1.5 kg / cm ² or more, more preferably 1.8 kg / cm ² or more. There is no particular upper limit, but usually 5 kg / cm ²
It is about. The applied ultrasonic sound pressure is 0.2V or more,
The sound pressure is preferably 0.5 V to 3.0 V, and in general, it is preferable that the sound pressure be high. However, if the sound pressure is too high, the temperature becomes partially high due to caption, which causes fogging. The frequency is not particularly limited, but is usually 10 kHz or more,
Preferably, it is 20 kHz to 200 kHz. In addition, decompression degassing refers to deaeration by increasing the air bubble diameter in the coating solution, increasing the buoyancy, and degassing the inside of the tank (usually a liquid preparation tank or a storage tank). Depressurization conditions are -200 mmHg or lower pressure conditions,
Preferably, the pressure condition is -250 mmHg or lower, and the lowest pressure condition is not particularly limited, but is usually about -800 mmHg. Decompression time is more than 30 minutes,
It is preferably 45 minutes or more, and the upper limit is not particularly limited.

In the present invention, the image forming layer, the protective layer of the image forming layer, the undercoat layer and the back layer are described in JP-A-11-84.
No. 573, paragraphs 0204 to 0208, JP-A-20
Paragraph Nos. 0240 to 0241 of JP-A-00-47083
A dye can be contained for the purpose of preventing halation as described in (1).

Various dyes and pigments can be used in the image forming layer from the viewpoint of improving color tone and preventing irradiation. Although any dyes and pigments can be used for the image forming layer, for example, compounds described in paragraph No. 0297 of JP-A-11-119374 can be used. As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds to be used is determined depending on the desired absorption amount, but it is generally preferable to use them in the range of 1 × 10 ⁻⁶ g to 1 g per 1 m ² .

When an antihalation dye is used in the present invention, the dye has a desired absorption in a desired range, has a sufficiently low absorption in the visible region after treatment, and has a desirable absorbance spectrum shape of the back layer. Any compound can be used, if possible. For example, a compound described in paragraph No. 0300 of JP-A-11-119374 can be used. Further, as described in Belgian Patent No. 733,706, a method in which the concentration of a dye is reduced by erasing by heating, or as described in JP-A-54-17833, by erasing by light irradiation. A method of lowering the concentration or the like can also be used.

When the photothermographic material of the present invention is used as a mask when preparing a printing plate using a PS plate after the heat development, the photothermographic material after the heat development is exposed to the PS plate in a plate making machine under the exposure conditions for the PS plate. Information to set,
Information for setting plate-making conditions such as a transfer condition of a mask original and a PS plate is carried as image information. Therefore, said irradiation dye, halation dye,
The concentration (use amount) of the filter dye is limited to read them. Since this information is read by LED or laser, Dm of the wavelength range of the sensor
In (minimum concentration) needs to be low, and the absorbance needs to be 0.3 or less. For example, a plate making machine S-FNRIII manufactured by Fuji Photo Film Co., Ltd. uses a light source having a wavelength of 670 nm as a detector for detecting register marks and a barcode reader. In addition, plate making machine AP manufactured by Shimizu Seisakusho
A light source of 670 nm is used as a bar code reader of the ML series. That is, Dmi around 670 nm
When n (minimum density) is high, information on the film cannot be accurately detected, and a work error occurs in a plate making machine such as a conveyance failure and an exposure failure. Therefore, in order to read information with a 670 nm light source, Dmin around 670 nm needs to be low, and the absorbance at 660 to 680 nm after thermal development needs to be 0.3 or less. More preferably, it is 0.25 or less. The lower limit is not particularly limited, but is usually about 0.10.

In the present invention, any exposure apparatus used for imagewise exposure may be used as long as it can perform exposure with an exposure time of 10 ^-6 seconds or less. Generally, a laser diode (LD) and a light emitting diode are used. An exposure apparatus using (LED) as a light source is preferably used. In particular, LD has high output,
More preferable in terms of high resolution. Any of these light sources may be used as long as it can generate light of an electromagnetic wave spectrum in a target wavelength range. For example, in the case of LD, a dye laser, a gas laser, a solid laser, a semiconductor laser, or the like can be used.

The exposure in the present invention is performed by overlapping the light beams of the light source. The overlap means that the sub-scanning pitch width is smaller than the beam diameter. For example, the overlap is determined by changing the beam diameter to a half value width (FW) of the beam intensity.
HM), it can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient).
In the present invention, the overlap coefficient is preferably 0.2 or more.

The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a plane scanning method, or the like can be used. Also,
The channel of the light source may be a single channel or a multi-channel. However, a multi-channel having two or more laser heads is preferable in that high output is obtained and writing time is shortened. In particular, in the case of a cylindrical outer surface type, a multi-channel having several to several tens or more laser heads is preferably used.

The photothermographic material of the present invention has a low haze at the time of exposure and tends to generate interference fringes. As a technique for preventing the generation of the interference fringes, a technique disclosed in Japanese Patent Application Laid-Open No. Hei 5-113548, for example, in which a laser beam is obliquely incident on a photosensitive material, or WO95 / 3175.
A method using a multi-mode laser disclosed in, for example, Japanese Patent Application Laid-Open No. 4 (Kokai) No. 4 is known, and it is preferable to use these techniques.

The heat development step of the image forming method used in the present invention may be any method, but usually, the heat-developable photosensitive material exposed imagewise is heated and developed. As a preferred embodiment of the thermal developing machine to be used, a type in which the photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum is disclosed in Japanese Patent Publication No. 5-56499, Japanese Patent Laid-Open No. 9-292695, and Japanese Patent Laid-Open No. Developing machine described in Japanese Patent Application Laid-Open No. HEI 7-132 as a non-contact type.
No. 94, International Publication Nos. WO 97/28489, JP 97/28488 and JP 97/28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is from 80 to 250C, more preferably from 100 to 14C.
0 ° C. The development time is preferably from 1 to 180 seconds, more preferably from 5 to 90 seconds. Line speed is 1
It is preferably at least 40 cm / min, more preferably at least 150 cm / min.

As a method for preventing processing unevenness due to a dimensional change of the photothermographic material during thermal development, a method of using a temperature of 80 ° C. or higher
It is effective to adopt a method in which an image is not formed at a temperature of less than 15 ° C., heated for 5 seconds or more, and then thermally developed at 110 ° C. to 140 ° C. to form an image (a so-called multi-step heating method). .

When the photothermographic material of the present invention is subjected to thermal development processing, it is exposed to a high temperature of 110 ° C. or more, so that a part of the components contained in the material or a part of the components decomposed by thermal development may be reduced. Volatilizes. These volatile components may cause uneven development, corrode the components of the heat developing machine, precipitate at low temperatures, cause deformation of the screen as foreign matter, and adhere to the screen and become dirty. Is known to have a bad effect. As a method for eliminating these effects, it is known to install a filter in the heat developing machine and optimally adjust the flow of air in the heat developing machine. These methods can be used effectively in combination. International Publication WO95 / 30933, 97
Japanese Patent Application Laid-Open No. 21150/1990 and Japanese Patent Application Laid-Open No. 10-500496 disclose a filter cartridge having a first opening for introducing volatile components and having a binding opening and a second opening for discharging a volatile component. It is described to be used for a heating device for heating by heating. In addition, International Publication WO96 / 1
Japanese Patent Application Laid-Open No. 2213 and Japanese Patent Application Laid-Open No. 10-507403 describe the use of a filter combining a thermally conductive condensation collector and a gas-absorbing fine particle filter. In the present invention, these can be preferably used. U.S. Pat. No. 4,518,845 and Japanese Patent Publication No. 3-54331 disclose a device for removing vapor from a film, a pressurizing device for pressing the film against a heat transfer member, and heating of the heat transfer member. A configuration having an apparatus for performing the above is described. Further, International Publication WO98 / 27458 describes removing a component which increases fog volatilized from a film from the film surface. These can also be preferably used in the present invention.

FIG. 1 shows an example of the configuration of a heat developing machine used in the heat developing process of the photothermographic material of the present invention. FIG. 1 is a side view of the heat developing machine. The heat developing machine of FIG. 1 includes a carry-in roller pair 11 (an upper roller is a silicon rubber roller and a lower roller is an aluminum heat roller) for carrying the heat-developable photosensitive material 10 into a heating section while correcting and preheating the heat-developable photosensitive material 10 into a planar shape. It has a carry-out roller pair 12 that carries out the heat-developable photothermographic material 10 after the heat development to a flat shape and carries it out of the heating unit. The photothermographic material 10 has a carry-in roller pair 1
While being transported from 1 to the discharge roller pair 12, it is thermally developed. In the conveying means for conveying the photothermographic material 10 during the heat development, a plurality of rollers 13 are provided on the side where the surface having the image forming layer contacts, and the non-woven fabric (for example, Smooth surface 14 on which aromatic polyamide or Teflon (registered trademark) is bonded.
Is installed. The photothermographic material 10 is conveyed while the back surface is slid over the smooth surface 14 by driving a plurality of rollers 13 that come into contact with the surface having the image forming layer. A heater 1 is provided on the upper portion of the roller 13 and the lower portion of the smooth surface 14 so as to be heated from both sides of the photothermographic material 10.
5 is installed. As a heating means in this case, a plate heater or the like can be used. Although the clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, it is appropriately adjusted to a clearance that can transport the photothermographic material 10.
Preferably it is 0 to 1 mm.

Material of the Surface of Roller 13 and Smooth Surface 1
The member 4 is durable at high temperatures and may be anything as long as it does not hinder the conveyance of the photothermographic material 10, but the material of the roller surface is made of silicon rubber, and the member of the smooth surface is made of aromatic polyamide or Teflon (PTFE). Non-woven fabrics are preferred. It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely.

The heating section is composed of a preheating section A having a carry-in roller pair 11 and a heat development heating section B having a heating heater 15, but a preheating section upstream of the heat development processing section B. A is lower than the heat development temperature (for example, 10 to 3).
(Lower by about 0 ° C.), it is desirable to set the temperature and time to be sufficient to evaporate the amount of water in the photothermographic material 10 and to be higher than the glass transition temperature (Tg) of the support of the photothermographic material 10. It is preferable to set the temperature so that uneven development does not occur. The temperature distribution of the preheating section and the heat development section is preferably ± 1 ° C. or less, more preferably ± 0.1 ° C.
5 ° C. or lower is preferred. Further, a guide plate 16 is provided downstream of the thermal development processing section B, and a slow cooling section C having the carry-out roller pair 12 and the guide plate 16 is provided. Guide plate 16
Is preferably a material having a low thermal conductivity.
The cooling is preferably performed gradually so as not to cause deformation, and the cooling rate is preferably 0.5 to 10 ° C./sec.

Although the above has been described with reference to the illustrated examples, the invention is not limited thereto. For example, the thermal developing machine used in the present invention, such as that described in JP-A-7-13294, may have various structures. In the case of the multi-stage heating method preferably used in the present invention, in the above-described apparatus,
Two or more heat sources having different heating temperatures may be provided, and heating may be performed continuously at different temperatures. The photothermographic material of the present invention is described by a packaging material described in paragraphs 0014 to 0026 of JP-A-2000-206653, or described in paragraphs 0020 to 0045 of JP-A-2001-13632. Preferably, it is packaged by a packaging method.

[0166]

The present invention will be described more specifically with reference to the following examples. Materials, reagents, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

<Example 1><< Preparation of Silver Halide Emulsion A >> Alkali-treated gelatin (2700 ppm in terms of calcium content) was added to 700 ml of water.
The following) 11 g, 30 mg of potassium bromide and 1.3 g of sodium 4-methylbenzenesulfonate were dissolved and the pH was adjusted to 6.5 at a temperature of 45 ° C., and then 18.6 of silver nitrate
g of aqueous solution containing 159 ml of potassium bromide and 1 mol /
L, 5 × 10 ⁻⁶ mol of (NH ₄ ) ₂ RhCl ₅ (H ₂ O)
/ L and an aqueous solution containing 2 × 10 ⁻⁵ mol / L of K ₃ IrCl ₆ were added by a control double jet method over 6 minutes and 30 seconds while maintaining the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.5 g of silver nitrate, 1 mol / L of potassium bromide and 2 × 10 ⁻⁵ mol / L of K ₃ IrCl _6.
Was added over 28 minutes and 30 seconds by the control double jet method while maintaining the pAg at 7.7. Thereafter, the pH was lowered to cause coagulation and sedimentation, followed by desalting treatment, and 51.1 g of low molecular weight gelatin having an average molecular weight of 15,000 (calculated as 20 ppm or less) was added.
The pH was adjusted to 5.9 and pAg to 8.0. The obtained particles had an average particle size of 0.11 μm, a projected area variation coefficient of 9%,
Cubic particles having a (100) face ratio of 90%.

The thus-obtained silver halide grains were heated to 60 ° C., and 76 μmol of sodium benzenethiosulfonate per 1 mol of silver were added. Three minutes later, 71 μmol of triethylthiourea was added, followed by aging for 100 minutes.
-Hydroxy-6-methyl-1,3,3a, 7-tetrazaindene is 5 × 10 ⁻⁴ mol, and compound A is 0.17 g.
After the addition, the temperature was lowered to 40 ° C. Thereafter, the temperature was maintained at 40 ° C., and 4.7 × 10 ⁻² per mol of silver halide.
mol potassium bromide (added as aqueous solution), 12.8
× 10 ⁻⁴ mol of the following sensitizing dye A (added as an ethanol solution) and 6.4 × 10 ⁻³ mol of compound B (added as a methanol solution) were added with stirring, and after 20 minutes, rapidly cooled to 30 ° C. Thus, the preparation of silver halide emulsion A was completed.

[0169]

Embedded image

<< Preparation of Silver Behenate Dispersion A >> Behenic acid (product name: Edenor C22-85R) 8 manufactured by Henkel
7.6 kg, 423 L of distilled water, 5 mol / L NaOH
49.2 L of aqueous solution, tert-butyl alcohol 120
Were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, 206.2 L of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept at 10 ° C. 6
A reaction vessel containing 35 L of distilled water and 30 L of tert-butyl alcohol was kept at 30 ° C., and while stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were kept at a constant flow rate for 62 minutes, 10 seconds and 60 minutes, respectively. Added over minutes. At this time, only the silver nitrate aqueous solution was added for 7 minutes and 20 seconds after the start of the silver nitrate aqueous solution addition, and then the sodium behenate solution was started to be added. After 9 minutes and 30 seconds after the completion of the silver nitrate aqueous solution addition, only the sodium behenate solution was added. It was made to be added. At this time, the temperature inside the reaction vessel was 30 ° C.
And the solution temperature was controlled so as not to rise. Further, the piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the amount of steam was controlled so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After completion of the addition of the sodium behenate solution, the mixture is left to stir at the same temperature for 20 minutes,
The temperature was lowered to 25 ° C. Then, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid thus obtained was stored as a wet cake without drying. The morphology of the obtained silver behenate grains was evaluated by electron microscopic photographing. The average projected area diameter was 0.52 μm, and the average grain thickness was 0.14 μm.
m, scale-like crystals having a coefficient of variation of the average equivalent sphere diameter of 15%.

Next, a dispersion of silver behenate was prepared by the following method. For a wet cake having a dry solid content of 100 g, polyvinyl alcohol (trade name: PVA-21)
(7, average degree of polymerization: about 1700) 7.4 g and water were added to make the total amount 385 g, and the mixture was pre-dispersed with a homomixer. Next, the pre-dispersed undiluted solution is dispersed in a dispersing machine
The pressure of a microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) was adjusted to 1750 kg / cm ² , and the mixture was treated three times to obtain a silver behenate dispersion A. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the temperature of the refrigerant was adjusted to a desired dispersion temperature. The silver behenate particles contained in the silver behenate dispersion A thus obtained were particles having a volume-weighted average diameter of 0.52 μm and a coefficient of variation of 15%. For particle size measurement, use the Malvern Instrume
Performed with MaterSizerX manufactured by nts Ltd. When evaluated by electron microscopy, the ratio of the long side to the short side was 1.5, the grain thickness was 0.14 μm, and the average aspect ratio (the ratio of the circle equivalent diameter of the projected area of the grain to the grain thickness) was 5.1. Was.

<< Preparation of Solid Fine Particle Dispersion of Reducing Agent >> Reducing agent [1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane] 10k
g and 10 kg of a 20% by mass aqueous solution of denatured polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP203), 400 g of Surfynol 104E (manufactured by Nissin Chemical Co., Ltd.)
640 g of methanol and 16 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt was added. 4 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a solid fine particle dispersion of the reducing agent. The reducing agent particles contained in the dispersion thus obtained had a median diameter of 0.44 μm and a maximum particle diameter of 2.0 μm.
Hereinafter, the coefficient of variation of the average particle diameter was 19%. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion of Compound of the Formula (1) >> 10 kg of the compound of the formula (1) shown in Table 1 was mixed with a modified polyvinyl alcohol (Poval MP2 manufactured by Kuraray Co., Ltd.).
03), 639 g of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate, and Surfynol 104E (Nissin Chemical Co., Ltd.)
(G), 640 g of methanol and 16 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump, and a horizontal sand mill filled with zirconia beads having an average diameter of 0.5 mm (UVM-
2: Made by IMEX Co., Ltd.) for 5 hours, and water was added to adjust the concentration of the compound of formula (1) to 25% by mass to obtain a solid fine particle dispersion. 80% by mass of the particles contained in the dispersion thus obtained is from 0.1 μm to
1.0 μm, and the maximum particle size was 3.0 μm or less. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. Comparative compounds P-1 to P-6 were similarly dispersed.

[0174]

Embedded image

<< Preparation of Emulsified Dispersion of Compound Z >> Compound Z
10% of R-054 manufactured by Sanko Co., Ltd. containing 85% by mass of
g and 11.66 kg of MIBK were mixed, and then replaced with nitrogen and dissolved at 80 ° C. for 1 hour. 25.52 kg of water, 12.76 kg of a 20% by weight aqueous solution of MP-203 of MP polymer manufactured by Kuraray Co., Ltd. and 0.44 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate are added to this solution.
Was added and emulsified and dispersed at 20 to 40 ° C. and 3600 rpm for 60 minutes. In addition, Surfynol 104
E (manufactured by Nissin Chemical Co., Ltd.) 0.08 kg and water 47.94 k
g was added and distilled under reduced pressure to remove MIBK, and then the concentration of compound Z was adjusted to 10% by mass. The particles of compound Z contained in the dispersion thus obtained had a median diameter of 0.19 μm, a maximum particle diameter of 1.5 μm or less, and a variation coefficient of the particle diameter of 17%. The resulting dispersion had a pore size of 3.0.
Filtration was performed with a μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of dispersion of 6-isopropylphthalazine compound >> Modified polyvinyl alcohol (Poval MP, manufactured by Kuraray Co., Ltd.) while stirring 62.35 g of water at room temperature
203) 2.0 g was added so as not to form a lump, and stirred and mixed for 10 minutes. Thereafter, the mixture was heated and heated up to an internal temperature of 50 ° C., and then stirred for 90 minutes at an internal temperature of 50 to 60 ° C. to be uniformly dissolved. The internal temperature was lowered to 40 ° C. or less and polyvinyl alcohol (Kuraray Co., Ltd., PVA-21)
2. 5.5 g of a 10% by mass aqueous solution), 25.5 g of sodium tripropylnaphthalenesulfonate (a 20% by mass aqueous solution).
0 g and 6.15 g of 6-isopropylphthalazine (a 70% by mass aqueous solution) were added, and the mixture was stirred for 30 minutes to obtain a transparent dispersion 10
0 g was obtained. The obtained dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and then used for preparing the following coating liquid.

<< Preparation of solid fine particle dispersion of compound of formula (2) >> 1 kg of Poval PVA-217 manufactured by Kuraray Co., Ltd. and 36 kg of water were added to 4 kg of the compound of formula (2) and mixed well. To make a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 12 hours, and then 4 g of benzoisothiazolinone sodium salt was added. Water was added to adjust the nucleating agent concentration to 10% by mass to obtain a solid fine particle dispersion of the nucleating agent. Of the particles contained in the dispersion thus obtained, 80% by mass was 0.1 μm to 1.0 μm, and the maximum particle diameter was 3.0 μm or less. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. Comparative compounds R-1 to R-3 were similarly dispersed.

[0178]

Embedded image

<< Preparation of dispersion of solid fine particles of development accelerators W1 and W2 >> 10 kg of development accelerator W1, 10 kg of a 20% by mass aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), and 20 kg of water were added. do it,
The slurry was mixed well to form a slurry. The slurry was fed by a diaphragm pump, dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 5 hours, and then water was added thereto to add a development accelerator H. The concentration was adjusted to 20% by mass to obtain a solid fine particle dispersion of the development accelerator H. The organic polyhalogen compound particles contained in the dispersion thus obtained had a median diameter of 0.5 μm, a maximum particle diameter of 2.0 μm or less, and an average particle diameter variation coefficient of 18%. The development accelerator W2 was dispersed in the same manner, and had a median diameter of 0.5 μm, a maximum particle diameter of 2.0 μm or less, and a coefficient of variation of the average particle diameter of 17%. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Coating Solution for Image Forming Layer >> The following binder, material and silver halide emulsion were added to 1 mol of silver of the silver behenate dispersion A prepared above.
Water was added to obtain an image forming layer coating solution. After completion, degassing under reduced pressure was performed at a pressure of 0.54 atm for 45 minutes. Coating liquid p
H was 7.7 and viscosity was 50 mPa · s at 25 ° C.

Binder; SBR latex 397 g as solid content (St / Bu / AA = 68/29/3 (% by mass), glass transition temperature 17 ° C. (calculated value), Na ₂ S ₂ O ₈ as polymerization initiator Use, pH: adjusted to 6.5 using NaOH, average particle diameter: 118 nm) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane As a solid content, 149 0.5 g Compound of formula (1) or comparative compound P-1 to P-6 Kind and amount (mol) described in Table 1 Sodium ethylthiosulfonate 0.47 g Benzotriazole 1.02 g Polyvinyl alcohol (manufactured by Kuraray Co., Ltd.) PVA-235) 10.8 g 6-isopropylphthalazine 12.8 g Compound Z 9.7 g as solids Compound of formula (2) or comparative compound R-1 to R-3 Type and amount (mol) described in Table 2 Dye A (added as a mixture with low molecular weight gelatin having an average molecular weight of 15,000) Coating amount at which the optical density at 783 nm becomes 0.3 ( The solid content is 0.40 g as a guide) Silver halide emulsion A 0.06 mol as Ag amount Compound A as preservative 40 ppm in coating solution (2.5 mg / m ² as coating amount) 1 as total solvent amount in methanol coating solution 2% by mass as a total solvent amount in a coating solution of mass% ethanol. The pH was adjusted using NaOH as a pH adjuster. (The glass transition temperature of the coating film was 17 ° C.)

[0182]

Embedded image

<< Preparation of Coating Solution for Protective Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2
-Hydroxyethyl methacrylate / acrylic acid = 5
8.9 / 8.6 / 25.4 / 5.1 / 2 (% by mass) of a polymer latex solution (copolymer having a glass transition temperature of 46
° C (calculated value), 21.5% by mass as a solid content, 100 ppm of compound A, and 15% by mass of a compound D as a film-forming aid with respect to the solid content of the latex. Was adjusted to 24 ° C., and an average particle diameter of 116 nm) was added to 943 g of water to give Compound E1.62.
g, 114.8 g of organic polyhalogen compound C aqueous solution, 17.0 g of organic polyhalogen compound A as solid, 0.69 g of sodium dihydrogen orthophosphate dihydrate as solid, and development accelerator W1 as solid As 11.55
g, matting agent (polystyrene particles, average particle size 7 μm, variation coefficient of average particle size 8%) 1.58 g and polyvinyl alcohol (Kuraray Co., Ltd., PVA-235) 29.3
g, and water was further added to prepare a coating solution (containing 0.8% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. The coating solution had a pH of 5.5 and a viscosity of 45 mPa · s at 25 ° C.

<< Preparation of Coating Solution for Lower Overcoat Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Mass%) of a polymer latex solution (copolymer, glass transition temperature: 46 ° C. (calculated value), solid content: 21.
5% by mass, 100 ppm of compound A, and compound D as a film-forming auxiliary in an amount of 1% based on the solid content of the latex.
Water was added to 625 g of 5% by mass, the average transition particle diameter of the coating liquid was 24 ° C. and the glass transition temperature was 24 ° C., 0.23 g of compound C, 0.13 g of compound E, 11.7 g of compound F, 2.7 g of compound H and 11.5 g of polyvinyl alcohol (PVA-235, manufactured by Kuraray Co., Ltd.)
Was added, and water was further added to prepare a coating solution (containing 0.1% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. The coating solution had a pH of 2.6 and a viscosity of 30 mPa · s at 25 ° C.

<< Preparation of Coating Solution for Upper Overcoat Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Mass%) of a polymer latex solution (copolymer, glass transition temperature: 46 ° C. (calculated value), solid content: 21.
5% by mass, 100 ppm of compound A, and compound D as a film-forming auxiliary in an amount of 1% based on the solid content of the latex.
Water was added to 649 g of 5% by mass and an average particle diameter of 116 nm (the glass transition temperature of the coating solution was set at 24 ° C.), and carnava wax (manufactured by Chukyo Yushi Co., Ltd., Cellosel 52)
4: less than 5 ppm as silicone content) 30% by mass
18.4 g of solution, 0.23 g of compound C, 1.85 g of compound E, 1.0 g of compound G, matting agent (polystyrene particles, average particle diameter 7 μm, coefficient of variation of average particle diameter 8%)
3.45 g and polyvinyl alcohol (Kuraray Co., Ltd.)
Co., PVA-235) was added, and water was further added to prepare a coating solution (containing 1.1% by mass of a methanol solvent). After completion, vacuum degassing is performed at a pressure of 0.47 atm for 60
Minutes. The coating solution has a pH of 5.3 and a viscosity of 2 at 25 ° C.
It was 5 mPa · s.

[0186]

Embedded image

<< Preparation of Polyethylene Terephthalate (PET) Support with Back / Undercoat Layer >> (1) Preparation of PET Support Using terephthalic acid and ethylene glycol, the intrinsic viscosity IV = 0.66 (phenol / Tetrachloroethane = 6/4 (mass ratio) at 25 ° C) to obtain polyethylene terephthalate. This was pelletized, dried at 130 ° C. for 4 hours, and then melted at 300 ° C.
After being extruded from the die, it is quenched and the film thickness after heat setting is 12
An unstretched film having a thickness of 0 μm was produced.
This is longitudinally stretched 3.3 times using rolls with different peripheral speeds.
Then, a transverse stretching was performed 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds, and relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling is performed on both ends, and 4.8 k
g / cm ² . Thus, the width 2.4
m, length 3500 m, thickness 120 μm, roll-shaped PE
A T support was obtained.

(2) Preparation of Undercoat Layer and Back Layer Undercoat First Layer The above PET support was subjected to a corona discharge treatment at 0.375 kV · A · min / m ² , and a coating solution having the following composition was applied to the PET support. .2 ml / m ² on a support,
C. for 30 seconds, 150.degree. C. for 30 seconds, and 185.degree. C. for 30 seconds.

Latex-A 280 g KOH 0.5 g Polystyrene fine particles (average particle diameter: 2 μm, coefficient of variation of average particle diameter 7%) 0.03 g 2,4-dichloro-6-hydroxy-s-triazine 1.8 g Compound Bc -C 0.097g Distilled water Amount that total amount becomes 1000g

Second layer of undercoat A coating solution having the composition shown below was applied onto the first layer of undercoat so as to have a concentration of 5.5 ml / m ^2, and was applied at 125 ° C. for 30 seconds for 150 seconds.
It dried at 30 degreeC for 30 second and 170 degreeC for 30 second.

Deionized gelatin (Ca ²⁺ content: 0.6 ppm, jelly strength: 230 g) 10 g Acetic acid (20% by mass aqueous solution) 10 g Compound-Bc-A 0.04 g Methyl cellulose (2% by mass aqueous solution) 25 g Polyethyleneoxy compound 3g Distilled water Amount that totals 1000g

Back 1st layer 0.375 kV ·
A · min / m ² of corona discharge treatment is applied, and a coating solution having the following composition is applied to the surface so as to be 13.8 ml / m ^2, and is applied at 125 ° C. for 30 seconds, 150 ° C. for 30 seconds, 185 Dry at 30 ° C. for 30 seconds.

23 g of a 30% by mass aqueous dispersion (Julima ET410, manufactured by Nippon Pure Chemical Co., Ltd.) 23 g of alkali-treated gelatin (molecular weight: about 10,000, Ca ²⁺ content: 30 ppm) 4.44 g deionized gelatin (Ca ²⁺ content: 0.4) 0.84 g Compound-Bc-A 0.02 g Dye-Bc-A (adjusted to an optical density of 1.33 to 1.4 at 783 nm) As a guide 0.88 g Polyoxyethylene phenyl ether 1.7 g Water-soluble melamine compound (8% by mass aqueous solution) (Sumitomo Chemical Co., Ltd., Sumitex Resin M-3) 15 g Water dispersion of needle-like particles of Sb-doped SnO ₂ (FS-10D, manufactured by Ishihara Sangyo Co., Ltd.) 24 g) Polystyrene fine particles (average particle size: 2 μm, coefficient of variation of average particle size: 7%)

Back second layer A coating solution having the composition shown below was applied onto the first back layer so as to have a concentration of 5.5 ml / m ^2, and was applied at 125 ° C. for 30 seconds at 150 ° C.
For 30 seconds and 170 ° C. for 30 seconds.

30% by mass aqueous dispersion (Julima ET410, manufactured by Nippon Pure Chemical Co., Ltd.) 57.5 g Polyoxyethylene phenyl ether 1.7 g Water-soluble melamine compound (8% by mass aqueous solution) (Sumitomo Chemical Industries, Ltd.) , Sumitex Resin M-3) 15 g 30 mass% aqueous solution (Cellosol 524, manufactured by Chukyo Yushi Co., Ltd.) 6.6 g Distilled water The amount that the total amount becomes 1000 g

Back third layer The same coating solution as that of the first undercoat layer was applied on the second back layer so as to have a concentration of 6.2 ml / m ^2.
C. for 30 seconds and 185.degree. C. for 30 seconds.

Fourth Back Layer A coating solution having the composition shown below was applied onto the third back layer so as to have a concentration of 13.8 ml / m ^2.
It dried at 30 degreeC for 30 second and 170 degreeC for 30 second.

Latex-B 286 g Compound-Bc-B 2.7 g Compound-Bc-C 0.6 g Compound-Bc-D 0.5 g 2,4 Dichloro-6-hydroxy-s-triazine 2.5 g Polymethyl methacrylate (10 Mass% aqueous dispersion, average particle diameter 5 μm, coefficient of variation of average particles 7%) 7.7 g distilled water Total amount is 1000 g

[0199]

Embedded image

Latex-A: Core-shell type latex having a core part of 90% by weight and a shell part of 10% by weight Core part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 93
/3/3/0.9/0.1 (mass%) copolymer shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 8
8/3/3/3/3/3 (% by mass) copolymer Weight average molecular weight 38,000 Latex-B: methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate /
Acrylic acid = 59/9/26/5/1

(3) Heat treatment for transportation (3-1) Heat treatment PE thus prepared with a back / undercoat layer
The T support was placed in a heat treatment zone with a total length of 200 m set at 160 ° C., and transported at a tension of 2 kg / cm ² and a transport speed of 20 m / min. (3-2) Post-heat treatment After the heat treatment, post-heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and winding was performed. The winding tension at this time was 10 kg / cm ² .

<< Preparation of Photothermographic Material >>
Undercoat on the side of the PET support on which the second layer has been applied
On the layer, the specification of JP-A-2000-002964 is described.
Using the slide beat coating method disclosed in FIG.
Then, the above-mentioned coating solution for image forming layer was coated with a coating amount of 1.5 g / m
^TwoIt was applied so that Furthermore, the protective layer
When the coating liquid was coated with a solid content of polymer latex of 1.29.
g / m^TwoSimultaneously with the coating solution for the image forming layer
Applied. Then, the lower overcoat is formed on the protective layer.
When the solid coating amount of the polymer latex is 1.
97g / m^TwoAnd the upper layer overcoat layer coating solution
The solid content of the polymer latex is 1.07 g / m^Two
Simultaneous layering with lower layer overcoat coating solution so that
It was applied to prepare a photothermographic material. Drying at the time of application
Dry-bulb temperature 70-75 ° C, dew point
14-25 ° C, liquid film surface temperature 35-40 ° C,
Horizontal drying zone until the drying point near the point where
(The support is 1.5 ° to 3 ° with respect to the horizontal direction of the coating machine)
Angle). Winding after drying, temperature 23 ± 5 ℃,
Performed under the condition of relative humidity 45 ± 5%,
Image formation according to the processing mode (image forming layer surface side outer winding)
The layer side was outside. The wrapping humidity of the photosensitive material is relative humidity.
At 20-40% (measured at 25 ° C)
The pH of the film surface on the image forming side of the material is 5.1, and the Beck smoothness is
850 seconds, pH of opposite membrane surface 5.9, Beck flat
The slip was 560 seconds.

<< Evaluation of Photographic Performance >> (Exposure Processing) The obtained photothermographic material is equipped with a semiconductor laser having a beam diameter (FWHM of ビ ー ム of the beam intensity) of 12.56 μm, a laser output of 50 mW, and an output wavelength of 783 nm. Using the single-channel cylindrical inner surface type laser exposure apparatus described above, exposure was performed at a mirror rotation number of 60000 rpm and an exposure time of 1.2 × 10 ⁻⁸ seconds. At this time, the overlap coefficient was 0.449, and the laser energy density on the photothermographic material surface was 75 μJ / cm ² . Using the laser exposure apparatus described above, test steps were output while changing the amount of light at 175 lines / inch.

(Heat Developing Process) The exposed photothermographic material was subjected to a heat developing process using the heat developing machine shown in FIG. The roller surface material of the thermal development processing part is silicon rubber,
The smooth surface was made of Teflon nonwoven fabric, and the line speed of the conveyance was set at 150 cm / min. Preheating section 12.2
Seconds (The drive systems of the preheating unit and the heat development unit are independent, and the speed difference between the heat development unit and the heat development unit is set to -0.5% to -1%.
The temperature setting and time of the metal roller of each preheating section are as follows: the first roller temperature is 67 ° C, 2.0 seconds, the second roller temperature is 82 ° C,
2.0 seconds, third roller temperature 98 ° C, 2.0 seconds, fourth roller temperature 107 ° C, 2.0 seconds, fifth roller temperature 115 ° C, 2.0 seconds, sixth roller temperature 120 ° C, .
0 sec), a heat development process was performed at 120 ° C. (surface temperature of the photothermographic material) for 17.2 seconds, and a slow cooling unit was performed for 13.6 seconds. The temperature accuracy in the width direction was ± 0.5 ° C. The temperature of each roller was set to be 5 cm longer on both sides than the width of the photothermographic material (for example, 61 cm in width), and the temperature was applied to that portion so that the temperature accuracy was improved.
In addition, since the temperature drop at both ends of each roller is severe,
The part that is 5 cm longer than the width of the photothermographic material is set so that the temperature is 1-3 ° C. higher than the center of the roller,
Care was taken so that the image density of the photothermographic material (for example, within a width of 61 cm) was uniform.

(Photo-heat treatment after thermal development processing) For the photosensitive material after exposure and thermal development, a light stability tester LST-300 manufactured by Tokyo Rika Kikai Co., Ltd. (light source: a fluorescent lamp for color evaluation manufactured by Toshiba Corporation) (FLR40S-N-EDL / M) at 40 ° C. and a relative humidity of 50% for 24 hours. The illuminance at the position of the photothermographic material was 8,500 Lux.

(Dark heat treatment after thermal development) The photosensitive material after exposure and thermal development was subjected to a dark place at 60 ° C. and a relative humidity of 5 ° C.
It was left for 24 hours under the condition of 0%.

(Evaluation method) Dmin (fog) of image,
For Dmax (maximum density), see Macbeth TD904
The measurement was performed using a densitometer (visible density). The sensitivity was represented by the reciprocal of the exposure amount giving a density of 1.5, and was defined as S1.5. Sample No. The photographic sensitivity of 1 is relatively expressed as 100, and the higher the value, the higher the sensitivity. As an index (γ: gradation) indicating the contrast of the image, Dmin + density of the characteristic curve of 0.
The point of Dmin + density 3.0 was connected by a straight line from the point 3 and the slope of this straight line was expressed as a γ value. That is, γ =
(3.0-0.3) / (log (exposure to give a density of 3.0) -log (exposure to give a density of 0.3)), and the higher the γ value, the harder the photographic characteristics. Is shown. Regarding the evaluation of the storage stability before the development processing, two sets of each of the heat-developable photosensitive materials, which were adjusted to 25 ° C. and a relative humidity of 40%, cut into a sheet state, stacked three times, and placed in a moisture-proof bag, were prepared. The photothermographic material was stored at 50 ° C. for 4 days, and then the above-described exposure and heat development were performed on the photothermographic material before storage and the central portion (second sheet) of the three sheets after storage, and the same evaluation was performed. . Practically, it is preferable that Dmin is 0.15 or less, Dmax is 4.0 or more, and the contrast is 15 or more.

Table 1 shows the results of the above evaluations for each photothermographic material.

[0209]

[Table 1]

As shown in Table 1, the photothermographic material satisfying the conditions of the present invention has a low Dmin, a high Dmax (maximum density), a high contrast (γ), and photographic properties due to storage before and after thermal development. It can be seen that the fog rise is small even in the forced thermoprocessing for predicting the fog.

Example 2 << Preparation of Coating Solution for Image Forming Layer >> The following binder, material and silver halide emulsion A were added to 1 mol of silver of silver behenate dispersion A prepared in Example 1. Then, water was added to obtain an image forming layer coating solution. After completion, degassing under reduced pressure was performed at a pressure of 0.54 atm for 45 minutes. The coating solution has a pH of 7.3 to 7.7 and a viscosity of 40 to 50 mPa · s at 25 ° C.
Met.

Binder; SBR latex (St / Bu / AA = 68/29/3 (% by mass), using Na ₂ S ₂ O ₈ as a polymerization initiator) 397 g of 1,1-bis (2- (Hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 148.0 g as solid content Compound of formula (1) Kind and amount (mol) shown in Table 2 Development accelerator W2 As solid content 5 g sodium ethyl thiosulfonate 0.3 g benzotriazole 1.2 g polyvinyl alcohol (PVA-235 manufactured by Kuraray Co., Ltd.) 10.8 g 6-isopropylphthalazine 14.0 g Compound Z 9.6 g as a solid content Compound C 0.2 g Dye A (added as a mixture with low molecular weight gelatin having an average molecular weight of 15,000) Optical density at 783 nm is 0.3 Amount of coating (solids 0.40 g as a guide) Compound of formula (2) Kind and amount (mol) shown in Table 2 Silver halide emulsion A Ag amount 0.06 mol Compound A as preservative 40 ppm in coating solution (2.5 mg / m ² as coating amount) 1% by mass as total solvent amount in coating solution of methanol ² % by mass as total solvent amount in coating solution of ethanol NaOH was used as a pH adjuster. (The glass transition temperature of the coating film was 17 ° C.)

<< Preparation of Coating Solution for Lower Protective Layer >> Butyl acrylate / methyl methacrylate = 42/58 (% by mass)
Ratio, average particle size 110 nm, mass average molecular weight 800,00
Water) was added to 900 g of a polymer latex solution (0) (a glass transition temperature of a copolymer of 30 ° C., a solid content concentration of 28.0% and 100 ppm of compound A), and 0.2 g of compound E and 0.2 g of polyvinyl alcohol (Kuraray (Kuraray ( Ltd., P
VA-235) was added, and water was further added to prepare a coating solution (containing 0.5% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. The coating solution has a pH of 5.2 and a viscosity of 35 m at 25 ° C.
Pa · s.

<< Preparation of Coating Solution for Upper Protective Layer >> Butyl acrylate / methyl methacrylate = 40/60 (% by mass)
Ratio, average particle size 110 nm, mass average molecular weight 800,00
0) in 900 g of a polymer latex solution (copolymer, glass transition temperature: 35 ° C., solid content: 28.0%, compound A: 100 ppm), carnava wax (manufactured by Chukyo Yushi Co., Ltd., Cellosol 524: silicone) The content is less than 5 ppm).
g, 0.3 g of compound C, 1.2 g of compound E, 25.0 g of compound F, 6.0 g of compound H, matting agent (polystyrene particles, average particle diameter 7 μm, coefficient of variation of average particle diameter 8)
%) And 40.0 g of polyvinyl alcohol (PVA-235, manufactured by Kuraray Co., Ltd.), and further water was added to prepare a coating solution (containing 1.5% by mass of a methanol solvent). After completion, degassing under reduced pressure is 0.47at.
m for 60 minutes. The coating solution has a pH of 2.4 and a viscosity of 2
It was 35 mPa · s at 5 ° C.

<< Preparation of Photothermographic Material >> On the undercoat layer of the PET support coated with the undercoat layer as described in Example 1, FIG. 1 in the specification of JP-A-2000-2964 is disclosed. Using the slide bead coating method
The image forming layer coating solution is coated with the protective layer lower layer coating solution on the polymer so that the coating silver amount is 1.5 g / m ^2.
The above-mentioned coating liquid for the upper layer of the protective layer is further coated with a polymer such that the solid content of the latex is 1.0 g / m ^2.
The image forming layer and the lower layer and the upper layer of the protective layer were simultaneously coated in three layers so that the solid content of the latex was 1.3 g / m ² . The drying conditions at the time of application are as follows: the first drying zone (low-speed air drying area) has a dry bulb temperature of 70 to 75 ° C and a dew point of 9 to 2;
Drying is performed at a temperature of 3 ° C., a wind speed on the support surface of 8 to 10 m / s, and a liquid film surface temperature of 35 to 40 ° C., and the second drying zone (high-speed air drying area) has a dry bulb temperature of 65 to 70 ° C. 20-23
At 25 ° C. and a wind speed of 20 to 25 m / s on the surface of the support. The residence time in the first drying zone was 2/3 of the constant-rate drying period in this zone, and the zone was moved to the second drying zone and dried. The first drying zone is a horizontal drying zone (the support is at an angle of 1.5 ° to 3 ° with respect to the horizontal direction of the coating machine).
It is. The coating speed was 60 m / min. Winding after drying was performed under the conditions of a temperature of 25 ± 5 ° C. and a relative humidity of 45 ± 10%. The winding shape was adjusted to the subsequent processing form (image forming layer surface side outer winding), and the image forming layer surface side was turned out. The humidity of the wrapping of the photosensitive material is 20 to 40% relative humidity (25%).
Of the resulting photothermographic material, the pH of the film surface on the image forming side is 5.0, the Beck smoothness is 5000 seconds, the pH of the film surface on the opposite side is 5.9, and the Beck smoothness is 500. Seconds.

The coating method was changed and samples were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0219]

[Table 2]

As shown in Table 2, as in Example 1, the sample satisfying the conditions of the present invention showed good performance.

<Example 3> In place of the support used in Examples 1 and 2, the following support was used.
Samples were prepared in the same manner as in Examples 1 and 2, and heat-developed in the same manner as in Example 1. The photothermographic material of the present invention almost reproduced the results of Examples 1 and 2, and the effects of the present invention were apparent. Met.

<< Preparation of Polyethylene Terephthalate (PET) Support with Back / Undercoat Layer >> (1) Preparation of PET Support Using terephthalic acid and ethylene glycol, the intrinsic viscosity IV = 0.66 (phenol / Tetrachloroethane = 6/4 (mass ratio) at 25 ° C) to obtain polyethylene terephthalate. This was pelletized, dried at 130 ° C. for 4 hours, and then melted at 300 ° C.
After being extruded from the die, it is quenched and the film thickness after heat setting is 12
An unstretched film having a thickness of 0 μm was produced.
This is longitudinally stretched 3.3 times using rolls with different peripheral speeds.
Then, a transverse stretching was performed 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds, and relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling is performed on both ends, and 4.8 k
g / cm ² . Thus, the width 1.4
m, length 3500 m, thickness 120 μm, roll-shaped PE
A T support was obtained.

(2) Preparation of Undercoat Layer and Back Layer Coating liquids SA to C were prepared. On the Em coating side, 13.8 ml / m ^{2 in} the order of SC and SA from the support. , 6.
2 ml / m ² was applied. Further, on the BC side, 6.2 ml / m ² and 13.8 ml in the order of SA and SB from the support.
/ M ² was applied. Drying at 125 ° C. for 30 seconds, 150
C. for 30 seconds and 185.degree. C. for 30 seconds. Both surfaces of the PET support were subjected to a corona discharge treatment at 0.375 kV · A · min / m ² .

Coating Liquid SA The above latex-A 280 g KOH 0.5 g Polystyrene fine particles (average particle diameter: 2 μm, coefficient of variation of average particle diameter 7%) 0.03 g 2,4-dichloro-6-hydroxy-s- Triazine 1.8 g Compound-Bc-C 0.06 g Distilled water Amount that gives a total amount of 1000 g

Coating Solution SC Pesresin A520 (30% aqueous dispersion, manufactured by Takamatsu Yushi Co., Ltd.) 46 g Alkali-treated gelatin (molecular weight: about 10,000, Ca ²⁺ content: 30 ppm) 4.44 g Deionized gelatin (Ca ²⁺⁾ 0.84 g Compound-Bc-A 0.02 g Dye-Bc-A (adjusted to an optical density of 1.3 at 783 nm) Polyoxyethylene phenyl ether 1.7 g Water-soluble melamine compound (8% aqueous solution) (Sumitec Resin M-3, manufactured by Sumitomo Chemical Co., Ltd.) 15 g Sb-doped SnO ₂ 20% aqueous dispersion (FS-10D, manufactured by Ishihara Sangyo Co., Ltd.) 81.5 g Polystyrene fine particles (average Particle size: 2 μm, coefficient of variation of average particle size 7%) 0.03 g Distilled water The amount that the total amount becomes 1000 g

Coating liquid SB 27% aqueous dispersion (Mitsui Chemicals Co., Ltd., Chemipearl S120) 73.1 g 25% aqueous dispersion (Takamatsu Oil & Fats Co., Ltd., Pesresin A615G) 78.9 g Compound-Bc- B 2.7 g Compound-Bc-C 0.3 g Compound-Bc-D 0.25 g Water-soluble epoxy compound (Denacol EX521, manufactured by Nagase Kasei Kogyo Co., Ltd.) 3.4 g Polymethyl methacrylate (10% aqueous dispersion, average) (Particle diameter: 5 μm, coefficient of variation of average particle: 7%) 7.7 g Distilled water An amount that gives a total amount of 1000 g

(3) Heat treatment for transportation (3-1) Heat treatment PE thus prepared with a back / undercoat layer
The T support was placed in a heat treatment zone with a total length of 200 m set at 160 ° C., and transported at a tension of 2 kg / cm ² and a transport speed of 20 m / min. (3-2) Post-heat treatment After the heat treatment, post-heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and winding was performed. The winding tension at this time was 10 kg / cm ² .

<Example 4> (Preparation of Subbed Photographic Support) A corona discharge treatment of 8 W / m ² · min. The following undercoating coating solution a-1
Is applied so as to have a dry film thickness of 0.8 μm, and dried to form an undercoat layer A-1. On the other side, an undercoat coating solution b-1 which has been subjected to antistatic processing and has a dry film thickness of 0. It was applied so as to have a thickness of 8 μm, and was dried to obtain an antistatic processed undercoat layer B-1.

<< Undercoat Coating Solution a-1 >> Butyl Acrylate (30% by Mass) Tert-Butyl Acrylate (20% by Mass) Styrene (25% by Mass) 2-Hydroxyethyl Acrylate (25% by Mass) Copolymer Latex Liquid (Solid content 30%) 270 g (C-1) hexamethylene-1,6-bis (ethylene urea) 0.8 g Polystyrene fine particles (average particle size 3 μm) 0.05 g Colloidal silica (average particle size 90 μm) 0.1 g water Amount that totals 1L

<< Undercoat Coating Solution b-1 >> SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (30 mass%) Styrene (20 mass%) Glycidyl acrylate (40 mass%) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g hexamethylene-1,6-bis (ethylene urea) 0.8 g water The total amount becomes 1 L amount

Subsequently, the undercoat layer A-1 and the undercoat layer B-1
A corona discharge of 8 W / m ² · min is applied to the upper surface of the lower layer, and the lower layer upper layer coating solution a-2 shown below is coated on the lower layer A-1 so as to have a dry film thickness of 0.9 μm. As the upper layer A-2, the lower coating layer B-1 having an antistatic function is formed on the lower coating layer B-1 by applying the following lower coating layer coating solution b-2 to a dry film thickness of 0.2 μm.
-2.

<< Coating Solution for Undercoating Upper Layer a-2 >> Gelatin 3.6 g / m ² Mass (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( (Average particle size 3μm) 0.1g Water Amount that total amount becomes 1L

<< Lower Coating Layer Coating Solution b-2 >> (C-4) 60 g Latex liquid containing (C-5) as a component (solid content: 20%) 80 g Ammonium sulfate 0.5 g (C-6) 12 g Polyethylene glycol ( Weight average molecular weight 600) 6g Water Amount that total amount becomes 1L

[0232]

Embedded image

(Heat Treatment of Support) The above-mentioned undercoated support was subjected to the same heat treatment as in Example 1.

<< Preparation of Silver Halide Emulsion A '>> In the preparation of Silver Halide Emulsion A, the mixture was added by a control double jet method over 33 minutes while maintaining pAg of 7.7, and then 4-hydroxy-6-methyl was added. -1,3,3
a, 7-tetrazaindene was added in an amount of 5 × 10 ⁻⁴ mol,
Reduction sensitization was performed by adjusting the pH to 8 and pAg 6.5 with NaOH, followed by coagulation sedimentation using a gelatin coagulant, desalting treatment, and addition of 0.1 g of phenoxyethanol, pH 5.9 and pAg 7.5. To obtain a silver halide emulsion A '. The resulting grains are silver halide emulsion A
Average particle size, projected area variation coefficient,
0) The plane ratio and the ratio of twin grains.

(Preparation of Na Behenate Solution) In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid and 5.6 g of stearic acid were dissolved at 90 ° C. Next, 98 ml of a 1.5 mol / L aqueous sodium hydroxide solution was added while stirring at a high speed. Next, after adding 0.93 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. and stirred for 30 minutes to obtain a sodium behenate solution.

(Preparation of Preform Emulsion of Silver Behenate and Silver Halide Emulsion A ') 15.1 g of the above silver halide emulsion A' was added to the above sodium behenate solution, and the pH was adjusted to 8.1 with sodium hydroxide solution. After the adjustment, 147 ml of a 1M silver nitrate solution was added over 7 minutes, and the mixture was further stirred for 20 minutes, and ultrafiltration was performed to remove water-soluble salts. The resulting silver behenate was grains having an average grain size of 0.8 μm and a monodispersity of 8%. After the floc of the dispersion was formed, the water was removed, washed six times with water and removed, and then dried.

(Preparation of Photosensitive Emulsion) The preform emulsion thus obtained was divided, and 544 g of a solution of polyvinyl butyral (average molecular weight: 3,000) in methyl ethyl ketone (17% by mass) and 107 g of toluene were gradually added and mixed. 30 ° C., 10 ° C. at 4000 psi with a media disperser using a bead mill of 0.5 mm size ZrO _2.
Minutes of dispersion.

The following layers were simultaneously coated on both sides of the support to prepare a sample. The drying was performed at 60 ° C. for 15 minutes.

(Back side coating) On the B-2 layer of the support
Was coated with a liquid having the following composition. Cellulose acetate butyrate (10% methyl ethyl ketone solution) 15 ml / m^Two Dye-Bc-B 7mg / m^Two Dye-Bc-C 7 mg / m^Two Matting agent: Monodispersity 15% Average particle size 8 μm Monodispersed silica 90 mg / m^Two Fluorinated surfactant: C₈F₁₇(CH_TwoCH_TwoO)₁₂C₈F₁₇ 50mg / m ^Two Fluorinated surfactant: C₉F₁₇-C₆H_Four-SO_ThreeNa 10mg / m^Two

[0240]

Embedded image

(Coating on Photosensitive Layer Surface Side) Photosensitive layer 1: A solution having the following composition was coated on layer A-2 of the support so that the coated silver amount was 2.4 g / m ² . 240 g of the photosensitive emulsion described above Sensitizing dye B (0.1% methanol solution) 1.7 ml Pyridinium bromide perbromide (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1.7 ml 2- (4 -Chlorobenzoylbenzoic acid) (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml Compound of formula (1) used in Table 1 (3% methanol solution) 6.6 as solid content × 10 ⁻³ mol Compound of formula (2) used in Table 1 (3% methanol solution) 4.7 × 10 ⁻⁴ mol as solid content Hardening accelerator P 0.3 g Phthalazine 0.6 g 4-methylphthalic acid 0 0.25 g Tetrachlorophthalic acid 0.2 g Calcium carbonate having an average particle size of 3 μm 0.1 g 1,1-bis (2-hydroxy-3,5 -Dimethylphenyl) -2-methylpropane (20% methanol solution) 20.5 ml Isocyanate compound (Desmodur N3300, manufactured by Mobay Corporation) 0.5 g

[0242]

Embedded image

Surface protective layer: A solution having the following composition was coated simultaneously on the photosensitive layer. Acetone 5 ml / m ² methyl ethyl ketone 21 ml / m ² Cellulose acetate butyrate 2.3 g / m ² methanol 7 ml / m ² phthalazine 250 mg / m ² Matting agent: monodisperse degree of 10% average particle size 4μm monodisperse silica 5 mg / m ² CH ₂ = CHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO ₂ CH = CH ₂ 35 mg / m ² Fluorinated surfactant: C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 10 mg / m ² Fluorinated _{surfactants: C 8 F 17 -C 6 H} 4 -SO 3 Na 10mg / m 2

Using the sample after forming the coating film, removing the binder, and observing with an electron microscope by a replica method, the organic silver particles were found to have a major axis diameter of 0.5 ± 0.05 μm.
m, tabular grains having a minor axis diameter of 0.4 ± 0.05 μm and a thickness of 0.01 μm are monodispersity of 5%, which is 90% of all organic silver grains.
Particles. When a sample was prepared and evaluated by changing the coating method, a sample satisfying the conditions of the present invention showed good performance as in Example 1.

<Example 5> The samples used in Examples 1 to 4 were exposed to a cylindrical outer surface multi-channel (50 mW).
Equipped with 30 semiconductor laser heads, the laser energy density on the photothermographic material surface is 75 μJ / cm ² )
When the photothermographic material of the present invention substantially reproduced the results of Examples 1 to 4, the effect of the present invention was apparent.

<Example 6> The samples used in Examples 1 to 5 were subjected to a thermal development process using a dry film processor FDS-6100X manufactured by FUJIFILM Corporation, and similar evaluations were performed. The results similar to those described above were obtained, and the effect of the present invention was clear.

[0247]

According to the present invention, high sensitivity, low fog,
A photothermographic material having good storage stability before and after development can be provided. Therefore, according to the present invention, optimal photographic characteristics for photolithography can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a configuration of a heat developing machine used for a heat development process of a photothermographic material according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 heat-developed image forming material 11 carry-in roller pair 12 carry-out roller pair 13 roller 14 smooth surface 15 heating heater 16 guide plate A preheating section B heat development processing section C slow cooling section

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H123 AB00 AB03 AB23 AB28 BB00 BB27 BB28 CA05 CB00 CB03

Claims (8)

[Claims] 1. A photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, a binder, and a polyhalogenomethylsulfonyl compound represented by the following formula (1): And a compound represented by the following formula (2): Embedded image (In the formula (1), Z ¹ and Z ² each independently represent a halogen atom, A represents a hydrogen atom or a halogen atom, and R ¹
Is an alkyl group having 2 to 12 carbon atoms which may have one or more substituents, an alkenyl group having 2 to 12 carbon atoms which may have one or more substituents, or 1
Or 2 to 1 carbon atoms which may have two or more substituents
2 represents an alkynyl group. The substituent which the alkyl group, alkenyl group or alkynyl group represented by R ¹ may have is a halogen atom; an alkoxy group; a nitro group; an amino group optionally substituted by an alkyl group; an alkoxycarbonyl group; A silyl group; an alkylthio group; and one or more substituents selected from the group consisting of heterocyclic groups. ) (In the formula (2), Z ³ represents an alkyl group optionally having one or more substituents, an aryl group optionally having one or more substituents, or 1 or 2 Represents a heterocyclic group optionally having at least two substituents, and W represents an aryl group optionally having one or more substituents, or an alkyl group substituted with an electron-withdrawing group And M represents a counter cation.) 2. In the formula (1), Z ¹ and Z ² are each a bromine atom, and A is a hydrogen atom or a bromine atom.
The photothermographic material according to claim 1. 3. In the formula (1), R ¹ is an unsubstituted alkyl group having 2 to 12 carbon atoms, an unsubstituted alkenyl group having 2 to 12 carbon atoms or an unsubstituted alkynyl group having 2 to 12 carbon atoms. 3. The photothermographic material according to claim 1 or 2, wherein 4. In the formula (1), R ¹ is an unsubstituted alkyl group having 3 to 5 carbon atoms, an unsubstituted alkenyl group having 3 to 5 carbon atoms or an unsubstituted alkynyl group having 3 to 5 carbon atoms. The photothermographic material according to claim 1. 5. In the formula (1), -CONHR ¹ is-
^{_{SO 2 C (Z 1) (}} Z 2) A is in the meta position with respect photothermographic material according to claim 1. 6. The photothermographic material according to claim 1, wherein the photothermographic material is exposed for 10 ^-6 seconds or less when forming an image. 7. The photothermographic material according to claim 1, wherein the photothermographic material is exposed by a multi-beam having two or more laser heads. 8. The photothermographic material according to claim 1, wherein the photothermographic material is subjected to a heat development process at a line speed of 140 cm / min or more.